Summary
Holiday hasn't shown much playmaking skills through his first four seasons in the league. His assist to usage ratio (which measures how often a player gets an assist given how much they get the ball) has consistently been near the bottom of the league for a point guard, according to Cleaning the Glass. He has consistently taken a good amount of midrange shots and has not been effective from there, and has also really struggled to finish at the rim.

Holiday might best be served as a Patrick Beverley type - a point guard that relies offensively on high-usage wings, but defensively guards the opposing point guards. Holiday is a career 37% three-point shooter, so there's potential for him to provide some value as a spot-up shooter in that kind of limited role.

Holiday will be almost 26 years old as a free agent in 2022, so while he may not have the upside of some others players coming off their rookie contracts, it's likely you'll be getting Holiday for his prime over his next contract. However, since his minutes have decreased in recent years, and he was unable to get consistent minutes with the Suns, interest in him as a free agent may be limited.

Cap Considerations
Holiday will be a restricted free agent with a $11.9 million cap hold, $5.8 million Qualifying Offer and full Bird rights. I wouldn't expect Holiday's QO to come into play, but I wouldn't completely rule it out as it's not far off from what he might get in free agency.

There's also a chance that the Suns might not tender him the QO, which would make him an unrestricted free agent. Given the Suns' luxury tax situation and how far back Holiday is on the depth chart, I think them not tendering him the QO is the most likely scenario.

From other teams, Holiday is unlikely to get offers above the full MLE, possibly even the Taxpayer MLE, so teams without cap space will have the ability to sign Holiday. In addition, adding a 15% trade bonus, a player option, and some advances on his salary could make it more difficult for Phoenix to match, should they make him a restricted free agent.