Summary
Ibaka only played in 56 games over the past two seasons due to a back injury, so his health is a big question right now. Even once he got healthy, he struggled to be effective and was out of the playoff rotation for the Bucks in 2022.

Ibaka may not have the athleticism that he had back in his days with the Thunder, but if he's healthy he can still provide value as a stretch big that can also defend the rim. He won't sky high for blocks on defense, but he's still big enough and moves well enough to be an impact defender.

On offense, Ibaka isn't really a lob threat anymore and is almost exclusively a pick-and-pop big, but that skill is valuable as it forces opposing centers to step away from the rim to defend him, or can cause mismatches if the defense decides to switch.

Because he doesn't do much else other than shoot jumpers anymore on offense, his offensively value is pretty directly tied to whether or not he's hitting shots. Ibaka has shot well over the past two seasons, hitting 36% from three and 47% from midrange, with both numbers being above-average for a big, according to Cleaning the Glass.

As long as Ibaka can continue to be mobile enough to be a solid defender, and hit shots on the offensive end, he'll continue to be a sold player as he ages into his mid-30's. However, his health will certainly play a big part in that, and his lack of playoffs minutes in 2022 is not a great sign for him going forward.
 
Cap Considerations
Ibaka will be an unrestricted free agent with an $12.6 million cap hold and Early Bird rights. Since the Bucks will be operating over the salary cap, they will retain Ibaka's Early Bird rights until he is re-signed or signs elsewhere. The Bucks could offer Ibaka a starting salary of up to $17 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 Ibaka as even teams without cap space could possibly use any of the Non-Taxpayer MLE, Taxpayer MLE, or possibly even the Room MLE or Bi-Annual Exception to sign him. There's also a possibility that Ibaka could be available with just a minimum contract offer.