2. Salary Cap
Beyond not being able to match most teams looking for Watson, they do not have the space to make it happen. The Bears have one of the worst cap situations heading into the offseason. They have been pushing Khalil Mack money back for years and are running out of ways to pull money of the air.
Sure, in acquiring Watson, you actually get a cheap contract for a year or so. The issue is that once again, other teams take on that same contract. Other teams have way more cap space to not only make that happen but make the team better.
The Bears would have to lose veterans buy the bundle to add Watson. Heck, they would have to throw them in a trade as well.
Teams like the 49ers, Patriots, and Panthers have heaps more cap space to go with more draft captial. So, they can beat the Bears in a bidding war, and they can have the roster assembled to add him to it. They also can add other free agents.
You could argue it is more realistic that the Patriots sign Allen Robinson and trade for DeShaun Watson than the Bears bringing in both. They have more space and draft assets.