Got an ST in 88, was more than happy with it for gaming and general computing tinkering (eventually upgrading to a 4mb STE with 235mb hard drive) now by 91 I could see that many Amiga games were now slightly better than their ST versions and being an avid gamer started looking at an upgrade path but felt no need to 'upgrade' for the marginal difference the Amiga would offer so instead was planning to get a megadrive so borrowed a mates Megadrive for a couple of weeks and loved the quality of shooters on it but equally felt the library was a bit one dimensional and beyond lots more parallax didn't feel compelled enough to choose it especially given cart prices.
Most of my friends had Amigas so did continue to see it's library in the 90s but as you say very little lasting legacy, the early forays into 3d were pioneered and delivered better on my ST in the 80s and early 90s the Amiga when it finally emerged from the STs shadow seemed to offer a confused library of sub console quality console type games.
I eventually went on to own a snes and jaguar (doh!) before everything went 3d in the late 90s.
The trouble with the Amiga I feel was it was a bit better than the ST making it able to try and compete (poorly) with consoles so Amiga owners remained invested in gaming on it for far too long so there was a market to sustain a library which looked back upon now seems very poor. As you mention most of the good games were better on other platforms its exclusives / killer apps feel like weird curios now that offer little to those interested in actual gaming and gameplay.
Even its once vaunted sonic abilities when you listen back to much of its audio today seem amateurish with tons of poor quality sampling used that has dated badly in a way that in contrast the raw chip tune output from the ST seems to stand up to better. Nostalgia plays a big part here but playing audio to those that have no experience of either machine often results in non invested listeners stating the Amiga output isn't the one they prefer.
Its legacy for gaming is probably more to do with fostering a generation in Europe that learnt to code on the platform but then again that is heavily shared with the ST and 8 bit platforms. So in summary if you didn't own one very little reason to go back to its library today (I tried for a bit via emulation but quickly realised it was much more fun exploring games on other platforms)