Where am I going to meet the locals except at the local bars and restaurants? ;) But seriously, I've never understood the jab about "getting to know the locals", I don't really meet local strangers right now, why would I assume I'm going to while slow traveling? You mentioned later in the thread that you are expecting to retire and travel cheap--what are your plans for getting involved in the communities you will be visiting?
There's absolutely nothing wrong with not getting to know the locals. It's your trip, you can do whatever you want while you're on it.
However, to answer your question about where to meet locals, there's tons of stuff you can do while you're slow traveling if you've made a town or city your temporary home.
We've been on the road for almost 6 years now, slow traveling the world by motorcycle. We've pursued all of our interests and hobbies whenever we stop for a while. We took Spanish school in Mexico and when our language skills got good enough, we then joined a language exchange club in Guatemala with locals who wanted to practice their English. We'd meet up in coffee shops and we'd practice Spanish while our partner responded in English and we'd correct each other's grammar and improve our vocabularies. Best of all, it was free, except for the price of a coffee or two.
Practicing Spanish in GuatemalaIn Medellin, Colombia, we found a group that got together and practiced AcroYoga in the local park. They were all Spanish-speakers, but when you're doing an activity it's not really about having perfect grammar or the best vocabulary. Again... free. The best part is that we met some people that we got together socially with for dinner or drinks after Yoga was finished.
Acroyoga in MedellinWe lived in Chiang Mai, Thailand for 12 months in total (over two winters), so we really got integrated into that community. We joined a beach volleyball club that met at the local university every week. My hobby is photography, so I joined a photography club. My Thai is not very good, but there were many locals who spoke very good English, so I could converse with them. Free. My wife joined a hiking club and the only cost was the bus rental that took them to the trails and back, less than $5 a week.
Hiking club in Northern ThailandI love playing music. Jamming with our host in La Paz, MexicoRecently, we spent 3 months in Japan. We hooked up with a predominantly ex-pat motorcycle group that hosted monthly get togethers in bars/restaurants and group rides out in the countryside. There were some Japanese riders who also spoke English, so we got to know some locals without having to learn Japanese in such a short time. Free, except for the cost of a pint of beer and gas money.
We have a blog that has a pretty wide readership in the motorcycle community, so we get invited to a lot of local people's houses for accommodations or just a warm meal. While we were in Costa Rica, our host invited us to watch the local team play soccer against powerhouse Mexico. They managed against all odds to beat them and the resulting celebrations spilled out into the streets. Very fun!
Everyplace we stay, the host always takes us to "this place I know that has the best tacos/schweinshaxe/roti/pad see-ew/etc. that the tourists don't know about". And it's *always* better than the tourist traps.
We also volunteer our time. We were in Croatia for five months and opened up our apartment to foster stray dogs, before they are adoptedIn Thailand, we volunteered at a dog shelter to walk dogs to help burn off their energy (and also to play with them! :) It was a super-rewarding experience!Sometimes we sing for our supper. This is us doing a presentation of our trip in Mexico CityDoing a presentation to a classroom of Croatian schoolkidsWe normally do presentations to fellow motorcycle riders/travelers. These kids had such different questions about our trip. They wanted to know about camels in the Sahara Desert, cobras in the souks in Marrakesh, blue-footed boobies in the Galapagos, all the different animals we've encountered all over the world! :)
We've had very frank discussions with German locals about the Syrian refugee crisis. Then we've had the same dialog with our Greek hosts about it. Very different viewpoints. We've talked to people in England about Brexit. And then to Scots. Again, very different views. Many of those views are under-reported and under-represented in the mainstream news, for fear of political incorrectness, but when you get people alone in the homes, talking over a bottle of vino or cerveza, you get the true sense of what people really feel outside of the headlines.
We heard music coming from inside a warehouse while walking around Holguin, CubaWhen we peered inside, we saw these dancers and musicians rehearsing for a show later on in the week. They gave us a personal invitation to their concert! We made friends with one of the dancers and got together with him after the practice. Over a few beers, he became very candid about living under the Cuban government and how the people really felt about it.
Speaking out against the government is punishable by fine or imprisonment. Neighbours and family members are encouraged to report against one another. The stuff he was telling us about is not something that you'll read about in the papers or see hear about in touristy places. Obviously, these aren't pictures of him...
Our friend's dance troupe in concert!Getting to know the locals instead of being spoon-fed what the tour companies want you to consume is like like reading the entire book, instead of just glancing at the cover. While the covers are nice and glossy, sometimes the real soul and the truth of a place lies just beneath the surface and it takes just a bit a time but certainly not a lot of money to open the book.