This is not a good comparison. Nvidia doesn't have a fab, but they are the lead player in the AI chip space. Intel had both and look where it got them. TSMC has a good model, and you can basically take any of your designs for the same node and manufacture it in any of their plants. Same strategy can be applied to Samsung, and they already help a lot on the memory segment. The new HBM3E memory chips for H200s might be even coming from Samsung.
Intel was infected with marketing people who diseased the entire C-Suite and drained the company for 8 years without doing anything other than make up new marketing names for the 5000-11000 series of chips and their stagnant iGPUs. That level of thievery would kill any leading company. ..
Intel actually did a lot in the last decade. Skylake alone was a massive improvement over the previous generation. AVX-512, countless open source projects—not to mention Optane, which was one of the most radical innovations in hardware in years. They did some really cool stuff with Altera IP, but the market didn't really care for it as much as it probably should have. Much of the value of Mobileye happened under Intel's ownership, too.
You mention their iGPUs, but their iGPUs actually got radically better in the timespan you mention; Iris, if properly cooled and not memory-choked, was actually pretty decent for a lot of purposes.
It does and historically has had a pretty terrible board, and its management hasn't been the greatest, but people who complain about them doing nothing for most of a decade generally are making a reactionary take about the lack of post-Skylake microarchitectures, while ignoring that pretty much everyone's performance gains got swallowed by vulnerability mitigations for years because they care about video games more than safety.