I didn't suggest that signing Eovaldi directly makes it harder for us to develop starting pitchers. Like you yourself did there, I just acknowledged the latter as a contributing factor on why the former happened.How is re-signing your own FA a "substitute" for drafting or developing alternative options? It doesn't affect that process at all. It's not like signing somebody else's QO guy. I mean, yes, the fact that we've really struggled to develop starting pitching is the reason why we needed to sign Eovaldi, but that doesn't mean signing Eovaldi makes it any harder for us to develop starting pitching.
DD needs to sign/acquire/slot X player to fill Y MLB roster spot. If you genuinely need an answer for why going the FA-to-be process route there can still qualify as a poor substitute to having a quality cost controlled option to plug in, even when it's our own FA in question, you can start with the obvious example in why we aren't just simply resigning Craig Kimbrel right now to fill the back end bullpen hole letting him walk will create.