Maybe a little more perceived value, but you're right, they haven't proven anything.
The reason I say perceived value is even on draft day, the opinion of many scouts was that if Simons had waited a year, he would have been a lottery pick in 2019. In both summer league and preseason, Simons has done nothing to hurt that impression. The general consensus is that, in spite of his age, lack of experience and slight build, he's actually closer to being ready than most would have projected on draft night. Basically, at this point, he should have the same trade value as a 2019 late lottery pick, basically something in the 10 - 15 range, and as far as I can tell, no one else has offered a package for Butler that includes a top 15 2019 draft pick.
Trent Jr. looked great in summer league, but has looked lost in preseason. GMs recently voted him as the 4th best steal in the draft. So, he does have some perceived value, but at this point, that perceived value is, at best, a late 1st round pick, or more likely an early 2nd round pick (i.e. about where we picked him).
At this point, I'd be willing to give up Collins in a deal for Butler. Collins has great defensive instincts and I believe his shot will come around, but he has hands of stone. He REALLY struggles catching the ball, and at times has difficulty controlling rebounds. I mentioned this during summer league and hoped it was just due to nerves, trying to make his move before he catches the ball, etc, and hoped it would improve. It hasn't. If anything, he looks even worse in preseason. It just further proves he's the anti-Meyers. He has all the defensive instincts and skills Meyers lacks, but one thing Meyers does well is catch the ball (he also sets good screens). What he does with it after he catches it is a topic for a different discussion, but if you could graft Meyers' hands onto Collins body, you might have something special.
BNM