The Nets and Knicks rarely make trades and especially since Mikal Bridges is their best player, I doubt that they would ever consider trading him, but a Knicks fan can dream at least. But I'll explain the reasons why it might cross their mind in the team by team below.
Knicks: The Knicks have been looking for a star and who better than Mikal Bridges who would also complete the Villanova reunion on the Knicks (Brunson, Hart, DDV, Arcidiacono). He may not have made an All-Star team yet but he's certainly looked the part and is the 3 and D wing that the Knicks desperately need to both provide a boost on offense and be an elite defender who can guard the Dames and Tatums of the East. He gives the Knicks more size on the starting unit and also allows RJ to slide down to the 2 spot which should improve his game as well. The vibes on the team would be immaculate with all the Nova teammates and all are renowned for how professional they are and how well rounded their games are. I don't know if it makes them a contender but the Knicks would be a team that's greater than the sum of its parts and would be a tough out for any team that faces them. They also get Osman from the Spurs to give them more size on the second unit and have someone who can fill in for Randle and give him a rest. The Knicks have too many guards and I doubt that DDV and Hart are going anywhere and they are the type of players that Thibs loves. Losing IQ hurts but the writing was on the wall when he wasn't extended. Losing Grimes would also hurt but he needs to play for a team that will prioritize his development and Thibs isn't the coach for that.
Spurs: The Spurs desperately need a PG and they get two with IQ and Simmons. IQ is the real prize and is their PG of the future. He fits their timeline and could be just what they need after their point-Sochan experiment didn't work. They've reportedly been open to trading Johnson and have plenty of other wings who can take his place. They're also in no hurry to win now so taking on Simmons crazy contract isn't a dealbreaker for them. In some ways, it could be the perfect environment for him as there's no pressure for him to perform right away. They also get several FRPs from the Knicks in compensation for Johnson and for taking on Simmons contract to add to their already plentiful bounty of picks.
Nets: So this is the hardest case to make because Bridges is seen as the Nets cornerstone and they never want to trade with the Knicks. However, this trade gets them two young wings in Johnson and Grimes and the contracts of McDermott and Fournier are both expiring or have a team option for next year so they take on no long term salary. Grimes has a high ceiling as a 3 and D wing and has already done a great job of guarding some of the league's elite offensive stars and would be able to showcase his full potential and develop further under a coach like Vaughn who is more creative on offense than Thibs. Johnson has also put up great numbers and is a solid young player on a reasonable contract that will look even better as he ages and under the new CBA. Best of all they don't give up any picks and have plenty of tradeable contracts to make in a bid for another star AND they get Simmons contract off the books which allows them more flexibility for contract extensions and in the free agent market.
Thoughts?