UK London Libraries

i get this post doesn't really apply to anyone outside of london but i genuinely want advice and r/ london took my post down:

I've been getting back into reading and I don't want to keep having to buy books. I realised I should visit my local library, since everyone says they're shutting down and need all the visitors they can get yadda yadda yadda. There are two local to me, so I visit, and they're both a bit rubbish. They don't have an interesting, varied or big fiction collection (my main issue) and are weirdly loud (not a huge issue since I would prefer taking books out and reading them at home, but I still found it surprising enough to mention.)

I've heard there are some really nice libraries in central london, like the one in the Barbican. I'm wondering if travelling there and back (by tube) is worth the hassle. I tend to buy secondhand, so I can get a book for £2-6 if I'm good about it. Is central london's library fiction collections that good? Is it worth it? I already feel like a loser going to a library so I'm hesitant.