Understood. I wasn't explicit enough.
The only reason I can see to trade Brad is to significantly increase our flexibility -- presumably so that we can retool the team in a major way for a next generation. Swapping him for Klay isn't a move in that direction, obviously. In fact, it's a move in the opposite direction -- precisely b/c of that extra contract year at $43m.
Klay's contract reduces our flexibility for the next 3 years -- not hugely, but it can't be entirely ignored either. Then it significantly hampers us the 4th year.
That year will be Wall's 14th in the league & Klay's 13th. Those two geezers won't be leading us to contention (assuming we've re-signed John). Moreover, it's whistling in the wind to imagine that, as the years pass, it'll be easy to move Klay's contract (e.g. easier than moving Brad's if we had to).
If Klay Thompson was a much better player than Bradley Beal, & if that difference gave us a shot to contend for a title right now -- sure, why not? But, he isn't. &, even if he were, it wouldn't.
In fact, right now Klay Thompson is not as good a player as Bradley Beal. He was better than Brad his first few years in the league, to be sure -- but I think it's safe to attribute that edge to his being older than Brad by almost 3.5 years.
In short, Klay makes us older not younger, worse not better, more not less hampered in the future, etc. etc. etc. -- not to mention that he's coming off a serious injury. Wish him the best; don't want him in a Wizards uni.
Remember -- if you don't like the post above: blame Doc not me.