Ex FAANG Senior engineer here. I don’t think the gap between a senior and juniors is that big, and seniors shouldn’t be so complacent (if they were)
Real "senior" devs don't cargo cult.
The MBA'ification of various sectors keeps resulting in disaster & decline, but empowering craftspeople & laborers to do good seems to remain deeply unpopular by most businesses.
Whether businesses care enough to share ownership with the dev "resources" is a somewhat scary ongoing balance. It's sick to say, but to me it's unclear what concerted forces will help maintain experience & knowledge as a useful thing, amid a hyper-capitalism running amock. I hope my fears here are deeply unjustified.