The odd thing is that most starters have a claim at goodness, or even very goodness.
You look at a list of the top 100 starters and 90 percent of them were once All-Stars, or once finished in the top five in Cy Young balloting, or were top-five overall draft picks, or came up as top-five overall prospects, or were serious Rookie of the Year contenders. And most still have enough of that in them that it could re-emerge in any start.
Pitching is so fickle that almost everybody is one small tick away from being indominable, and one small tick away from being useless.
None of that is written to in any way excuse the Mets offensive ineptness, which is really bad. On the pitching side, however, the Mets aren't running Senga and Peterson out there for nothing.