Think about how many guards there are still available in FA right now:
Westbrook
Paul
Brogdon
Lillard
Payne
Payton II
Fultz
Shamet
Joseph
Of those players, 5/8 played important minutes in the playoffs last year. The other three were not in the playoffs, and Paul was 1/3 that started for the Spurs last season. The other two were injured for a significant portion of the season.
That doesn't even begin to touch on the RFA
Grimes
Giddey
Thomas
The first way of viewing this is that the league is very deep.
But the second is that maybe the guard position in the NBA is worse than we think it is. Maybe teams are changing guards every year right now because there aren't many guards that differentiate themselves from the pact in how they affect winning.
On the flip side, you have the Magic trading two rotation players and 4 first round picks for a guard that isn't even an all-star, but that guard has been proven to affect winning.
I think it just kinda' shows where the league is at.