A mortgage is a very definite "tie", for many years. I can't guess the market, but there is certainly not much talk about big increases in house prices here for the next couple years, so I don't think you need to buy now to avoid missing out. By the time you are 25, your Vanguard stash should have grown into a great deposit on a place to buy for yourself or a buy to let.
I also think your question might be less a financial question than a "what do I want to do with my life" question. Even though you like your job it's not particularly highly paid, as far as I recall there's no scope for progression, and I suspect there are other jobs out there which would suit you in the future just as well as this one does. That suggests to me that you are free to make other choices than buying property in the UK. You sound to me like the ideal candidate for a working visa for countries like Canada and Australia. They are only available to those under 26, so if you are interested in living in another country it's a great opportunity to try them out while earning. For the next couple of years you also have the right to work anywhere in the EU, perhaps make use that while it's still there?