People are not considering that the breaking of bounded accuracy is absolutely intentional, and is not inherently problematic.
Characters that invest heavily in doing something should be insanely good at it, and the game should be able to work despite the assumption that the PCs will succeed on those checks virtually all the time. It takes the ability from, "You need to roll reasonably well to do it and might fail" to "you'll rarely, if ever fail" - but we see that happen all of the time in other ways in D&D without it being problematic.
Characters want to sneak up on someone. At low levels, they're mostly reliant upon stealth. At higher levels, they get invisibility, silence, teleportation, modify memory, and other ways to do it that are more powerful. When a high level party teleports directly in front of a monster and launches a sneak attack when the monster had no reason to expect them, I can't imagine it not being a surprise - and that there may be no roll involved.
The inclusion of expertise wasn't some sneaky and hard to predict impact on the game - it is a very blatant issue and the ramifications of it were obvious from the start. They knew what they were doing, they intended to do it, and it works as intended.