Here is the list of top 5 hitters in all of baseball who have come available at age 26 (which Soto will turn after next season, just before becoming a FA) during the time the Ricketts family has owned the team:
Bryce Harper, Manny Machado (YMMV on whether or not he was a top 5 hitter, I would argue not, but he was probably close)
Harper had posted OPS+ of 133, 156, 114, and 198 the 4 years before FA. Machado ran his at 145, 108, 130, and 132
Soto's last 4 seasons were 158, 147, 175 and a 217 in the covid year... 142 the year before that, as a 20 year old
Even those 2 haven't produced consistently great numbers like Soto. And they were both available the same offseason with nearly every team bidding for them. I would imagine the Cubs made good, but not good enough, offers to both. But either way, comparing the FAs they've signed to Soto is irrelevant, because there have basically been 3 FAs like Soto that I can recall since 2000, those 2 and ARod when he signed with Texas for 10/252.