Tigers have the financial resources, so that's not the issue.
Right player being available is legitimately an issue. Even if we're among their top targets, which seems unlikely to me, maybe Kyle Tucker or Bo Bichette or Alex Bregman are not the answer for this team. Maybe Ha-Seong Kim or Jorge Polanco are better fits.
I'm not inside the organization, so I can't know for sure. I can only speculate on what they might be thinking, which is the main thing I like to do (rather than projecting my own desires on whatever I might declare the Tigers are most definitely thinking). But from the outside, I see a bunch of possible holes they would need to fill to put a championship-level team on the diamond, mainly, right field, center field, third base, shortstop, and maybe even first base depending on which Tork shows up next year. (Even the good Tork was worth barely two wins in 155 games last year, and that's the best one we have seen so far.) We also have the larger part of an effective bullpen to construct. We wouldn't be solving all those problems by signing a single top free agent, after which there would be multiple other holes.
Of course, the front office may be seeing things very differently from how I see them even as a relatively informed outsider. Heck, it is almost certain that they see things differently than I do. That's why I am wrong nearly all the time! 😁
All this said, I am not against signing Kyle Tucker or Bo Bichette or Alex Bregman. If we were to sign any of them, I'll be happy to trust that the Harris front office knows what they are doing, until they demonstrate to me that they do not.