ECS/AGA GFX was lacking in resolution and color compared to most VGA-cards of that era but could more than compete on speed.
ECS did have 640x480@60Hz capability however, albeit in 4 colours IIRC. For business use that would have been fine at the time, I know it would have been going up against 16 colour Win 3.1 systems eventually, but most people were still using DOS at that time.
So yes, if C= had woken up in 1990 or so and had invested heavily in modernizing HW and SW Amiga could have come out ahead by 95.
They didn't do that and so we ended with a minimal HW-update to late and an OS full of great concepts but also bugs and outright holes.
The problem was the lack of hardware design investment after the original Amiga came out. ECS was a tweak, AGA was a bit of a hack. Commodore recognised the value of a cost-down Amiga, the A600, but hadn't invested in the single-chip version of ECS, nor did they get it out at a suitable time - 1991 was probably a year too late. Commodore limited the range of Amigas too - A1200 and A4000/040 was either low-end, or very high end - the 030 version took a while to arrive and there was still a massive gap. An A1400 (A1200 in an A1000-style case, maybe 21MHz 020), as speculated at the time everywhere, was an obvious product (at £599 say) but never appeared. I think this was because they didn't have the money to do a proper job even in 1990.
Yeah, Commodore couldn't manage their way out of a paper bag filled with way out signs. Underinvestment and underselling the Amiga killed them. That foray into PCs showed a lack of commitment to their core range of computers. And that's just a small part of it.