For starters, it's neither yours nor mine place to tell anyone how they should feel about something.
Secondly, sure tanks have lost a fair bit of complexity. Boss positioning isn't really much of a thing anymore, but above all else, their core gameplay loop and entire facets of the role haven't regressed in the same way as healers have. Imagine if PLD launched in it's current iteration and then Shadowbringers hacked it right down to what it was in ARR. Now imagine if in Stormblood, Tanks defensive cooldowns got yeeted off the role entirely and dropped onto various DPS jobs (That for the most part didn't want them). Do you think they would be happy with that? I don't. IMO that perception is a big part of why so many old guard healers are so fed up at this point.
To be clear, I'm not sitting here trying to tell anyone that healers are the hardest done by role. I'm pointing out that it's a very easy assumption to make if you've been around and actively playing the game at a ~BCOB & Savage level since launch.
As for 'dealing with it'. That was the prevailing mentality back in Stormblood. 'Things will get better!', 'wait for the patch notes', 'wait for the post patch', 'wait for the next expansion!' etcetc. Gradually more and more people got fed up with that and well, here we are.