That’s part of it but Tom vetoed signing Bregman. Even during the Theo years they never topped $200 million in any free agent signing and settled for Lester when Scherzer was the better option. Theo also had more young talent at the MLB level allowing him flexibility to trade for Quintana and Chapman.
What you proposed is 100% true I agree with that but I wouldn’t rule out budgetary reasons completely. Cubs farm system isn’t exactly rich with talent. They want “sustained success”, “2032” and this entails prospect hugging at the expense of fully committing to a win now approach.