Roger Gracie comes to mind. I remember reading an article in Graciemag about how his superb escapes are the real reason why he is so good, and why no one has tapped him in a match since he was a blue belt. He's been taken down and put in bad positions and guys like Xande have attempted submissions on him, but he always gets out.
A skill differential is the result of practice. Don't put the cart before the horse. The reason why a black belt can easily escape the mount of a blue belt (and not vice versa) is not because he is a black belt, it is because he has practiced his escapes for many more repetitions.
It is entirely possible to have effective, high-percentage escapes that work against opponents who are the same belt level as you or even higher. You just have to practice them more.
And in no way am I implying that escaping is an ideal strategy that you rely on to win a match. It doesn't take many brain cells to realize that the best strategy is either takedown, pass guard, mount, submit or pull guard, submit. Escapes are what save your ass when your opponent is already in the process of doing that to you. They're the difference between almost losing and actually losing.
Your logic is strange to me because you're basically saying "don't practice your escapes because your escapes won't work because you aren't any better at them than your opponent is at holding a dominant position."
Well how do you expect your escapes to get good if you don't practice them?
There is no such thing as two competitors of exactly equal skill across the board. If you're that white belt who has blue belt-level escapes because you practiced them more, then you will have a much better chance of winning against your white belt opponents because they cannot hold you down or submit you.
Roger does not use that many escapes in his recent matches. I mean in the last Mundials, he was not even scored on. Therefore, he didn't have to escape from a dominant position even one time. In this year's Mundials, I think he gave up a takedown or something in a single match. But still he was not escaping from dominant positions.
I remember Roger pulling off some crazy escapes in the past, but Roger was not nearly as dominant back then. Now that he has ditched the escaping strategy and not even getting scored on, he has really gotten to the next level.
It is not possible to have high percentage escapes from dominant positions against guys who are the same skill as you. The only time that happens is when they are horrible at top game compared to your escapes, and that indicates a big skill gap. You might still get out, but if you can easily and consistently escape from an established mount, an established side control, back control with the hooks, etc., you are just fighting a crappy opponent.
Fighting from an inferior position is like giving your opponent a head start in a race. If you're Usain Bolt and you're racing me, you probably could give me a head start and still win. But when it's the Olympics, there is no room to give anybody even a little head start because you need every edge you can.
Your reasoning is that if you practice enough, you can eventually get so good that you can overcome the head start you gave your opponent. My reasoning is that at higher levels, it's not that realistic to expect that you can be that dominant over your opponents. The truth is that a lot of higher level matches end up being very close and won by an advantage or something. People like to imagine that if they work hard enough, they will develop into some sort of god who can consistently escape from bad positions. Yet for the vast majority of people, that will never happen. Maybe Roger is at that level, but no other top black belt in competition today is, let alone regular people.
I'm not saying that you should not train escapes. I am saying that it is much more productive to focus your training on preventing the bad positions in the first place than escaping from them once they are established. Being dominant from the top and having an impassable guard pay off way more in competition than having great escapes.