I've considered Igor to be a reputable source but the number of times that he's the first to report on these issues and giving incomplete data (such as lack of country of origin, exact models, case layout, room temps, etc..) I take what he says with a grain of salt until Gamers Nexus or DerBauer have an analysis.
I'm not saying Igor is doing anything sketchy, it's just becoming a trend.
And as others have asserted, GPUs are NOT simple like they used to be and TH recommending people just tear them apart and repaste since it's trivial is wrong and a generalization. As pointed out there are thermal pads to consider during reassembly where down to the millimeter and quality of themselves could end up killing your card (like reusing them), microtears or misalignment you can't even see if you use the wrong ones.
At the very least if you are hell bent on doing it, have GOOD digital calipers, not HarborFreight HS (Harbor Freight for our European friends is , hit or miss, like buying your tools from McDonald's. Measure the pad somewhere where it hasn't been compressed. Take pictures, don't add pads to every component you see.
GPUs aren't maintenance free but I don't believe in "fixing"/rebuilding them until there is a reason to. Anyone with equipment expensive enough that they'd be mad if it failed should be running something like HWInfo64 at all times, knowing their system and noticing when there are abnormalities.
I'm not just saying that because my 4090 HASN'T exhibited issues but because there are things in life where the old "If it ain't broke don't fix it" isn't just a saying but actually a better idea.
You are all free to do as you like, I'm not a Steve or Roman (Edited; Don't know why I thought his name was Stefan), I'm just your average PC guy who's been in and out of the desktop scene for years who knows what works for them and what doesn't (or is destructive) from personal experience.
TLDR; Take Igors report and TH suggestion with a grain of salt.