Lucas Vazquez, the fullback that really isn't. Is the criticism actually fair?

I've been wanting to hear opinion about Lucas that isn't a kneejerk reaction that comes off the back of a poor performance or a missed penalty (imagine the angry mob if we didn't make it past Atleti lol)

My case for Lucas

Footballers aren't Swiss Army knives, not all of them anyways. Certainly not Lucas.
He's our backup RB because once upon a time Carvajal was out injured and at the time we didn't have a backup RB (for the record, we still don't) so he was asked (or volunteered) to perform a role that isn't actually his. He did an okay/decent job back then, and sure some of us joke around calling him Lord Vazquez and Cafucas, but those names came from somewhere. In my mind, that can be considered some form of evidence that he performed well at some point.

Fast forward to today and his performances at RB have clearly taken a dip. That is undeniable. However, every time I see people calling for his head every game. None of this is on Lucas, it's on management. Every player that's played at RB over the last x number of seasons that is not named Dani Carvajal has not been an actual fullback; Lucas (not a fullback), Nacho (a versatile defender), Valverde (can do the job but is not a fullback), Asencio (versatile defender and really got a shot because of poor planning), Militao (CB).

Why is context thrown away every time his name comes up lately? You have a guy who is really one of the few options we have performing a role that isn't really his.
Again, I'm not excusing his performances, they have been shaky at best. However he is a winger in a fullback costume and I judge him that way. The same way I would judge Rodrygo, for example, if he were playing at fullback.

What am I missing here? Is the criticism fair? What are your thoughts?