A couple years ago I watched The Endless on Netflix and was looking for a way to watch Resolution - a micro-budget horror film from the same filmmakers (Justin Benson, Aaron Scott Moorhead) that is loosely connected to the later film - and found out about Tubi, which is now probably my favorite streaming service.
Not only is it free, but for someone who doesn't necessarily need the latest and "greatest" it is a treasure trove. It has films from the advent of cinema through to the last few years (there's even some brand new stuff, but not new blockbusters), and offers an incredible variety - low budget indies, 1920s silent films, Hollywood epics of yesteryear, overlooked films from now-popular filmmakers, schlock, documentaries, cult films, animated films, cheesy '80s films, old television shows.
Just a few examples of the hundreds of films I've watched on Tubi, off the top of my head: The Long Riders, Repo Man, American Pop, Ghost in the Shell, La La Land, Bull Durham, First Reformed, Mandy, Hunger, Bone Tomahawk, Mad Max, Malcolm X, Gattaca, Married to the Mob, Something Wild, In a Lonely Place, The Jolo Serpent Handlers, David Holzman's Diary, His Girl Friday, Tucker & Dale Vs. Evil, Thunderbolt and Lightfoot, Suspiria.
The catch is that you have to watch about ten minutes of adds sprinkled throughout the runtime. (It used to only stream in 720p but has upgraded to 1080p so for me that's no longer an issue at all.) They also started doing live sports, in-house productions, and other things now that Fox bought them, but I mostly stick to the movies. Highly recommended.