Summary
Trey Burke was signed by Dallas as a replacement player to play in the Orlando bubble in 2020, and ended up playing some of the best basketball of his career. He was a real scoring threat for the Mavs, and showed the ability to create his own shot at multiple levels.

However, that success has not continued since then. While he has shot a solid 37% from three in over the past two seasons, he continues to struggle to finish at the rim, which has been an issue for him throughout his career. For a little while there, when Burke found his way back into the league for the Knicks at the back end of the '17-'18 season, Burke showed improved body control around the rim, but he hasn't been able to make enough strides in that area to finish on a consistent basis.

He also has not developed into any sort of play-maker, and had one of the lowest assist rates in the league in '20-'21, according to Cleaning the Glass. That number improved slightly in '21-'22, but it was still below average and on a small sample size of minutes played.

While he has shown some improvement in his defensive effort, Burke has also never been a plus defender, partly due to his size. He was not in the playoff rotation in either 2021 or 2022.

Burke did not get much playing time in '21-'22, and the addition of Spencer Dinwiddie has only hurt his place in the depth chart. Because his value has dropped, I would expect Burke to opt in, and he could be a buyout candidate in 2023 if the Mavs can't find a trade for him.
 
Cap Considerations
Burke has a $3.3 million player option for next season, and if he declines that option he will be an unrestricted free agent with a $4.1 million cap hold and Early Bird rights (the contract Burke signed with Dallas for the Orlando Bubble doesn't count toward Bird Rights). If Burke opts for free agency, the Mavs could offer him a starting salary of up to 5% more than the average salary (likely around $10.9 million) using the Early Bird exception, which will be more than enough should they wish to bring him back.

Other teams will have multiple ways to sign Burke as even teams without cap space could possibly use any of the Non-Taxpayer MLE, Taxpayer MLE, Room MLE, or BAE to sign him. While I think Burke's market value is probably the minimum, I think if he opts out that means he knows he can get similar or more money than his player option, unless he's really just desperate to get out of Dallas.