It's been hard to accrue innings when the 2020 season got skipped, the 2021 minor league season got to a late start, and now prospects all around baseball are dropping like flies due to injuries. Everyone's prospects got a year older with no experience, and a lot of these guys played their first full season in 2019. I know this sounds like a load of excuses, but the pandemic has put a hold on the team's pitching pipeline and there's nothing they could do about it.
The current team's abysmal pitching has magnified the lack of minor league development... but as it has been stated by many others, the failure to supplement the big league pitching staff in 2016-2020 was more due to the complete and utter failures of Gonsalves, Jay, Stewart, Romero, and others. It can take a long time for young prospects to arrive - Balazovic was drafted in 2016, Enlow in 2017, for example - so not converting even a single one of the mid 2010s pitching prospects into something was a huge blow to the system. But those weren't Falvine's guys.