I’ve had a lot of mutts in my 60+ years and loved them all. That said, unless a breed is at the height of popularity and unscrupulus breeders are filling the market, the dog specifically bred for a purpose usually fills that nitch best imo. A good many breeds have been almost ruined by breeders nowdays - german shephard and their conformation is a good example and the cattle dogs raised for the show ring who have most of their suspicion bred out, but overall, I prefer a full breed dog.
And just my opinion. As regards health, you are just betting that you will get less health problems than end up with the health problems of both breeds.
No puppy mill runs genetic tests on heir breeding stock.
No “mutt” can guarantee health or longevity because the infinite variables in the alleles and loci are a crapshoot, at best.
Some mutts live long, healthy lives.
Just as many don’t but we’re not aware of this because nobody is keeping records to that effect, as breeders do.
“As regards health, you are just betting that you will get less health problems than end up with the health problems of both breeds.”