The Amiga was technologically outdated when Wolfenstein and Doom came out because Commodore had failed to update the platform for years. The A1200 was an extremely disappointing and late update (audio, for example, was still unchanged from the original design, almost a decade old). The original project to produce a next generation Amiga (with chunky mode and many other improvements) was in development hell for four years or more and was eventually canned. Commodore was poorly managed and, by 1992, it was close to bankruptcy after sleeping on extremely good products for years.
The problem of the Amiga was always Commodore, not hardware or software technicalities. Management at Commodore didn't understand their own product and didn't know what to do with it. All the perceived inadequacies of the platform (by 1992) were not that big of an issue. Sure, the platform had ton of custom hardware which made backwards compatibility (or introducing new features) hard in new designs, but consoles had the same problem and they worked around it (you add it, at an increased cost for the user, or just ignore it and invest in having great new software on launch). The Motorola CPUs were getting expensive and had difficulty competing with Intel, but Apple had the same problem and again, found a way around it. The OS was not designed for memory protection and it was not feasible to patch it in, but Microsoft had the same problem (well, they had it much worse) and found a way around it. And so on.
If Amiga had been managed by a competent company, by 1992 you would have a next generation computer (perhaps not compatible with the older Amigas, or with reduced compatibility) that would have no problem running things like Doom.
