Mixes are not bad, but sometimes people who breed "designer dogs" such as doodles and poos and whatever are not very ethical. It's unfortunately the case the majority of the time with designer dog breeders. They're in it for the money and little else. Betterment of the breed and healthy dog is typically not at the forefront of their mind. That doesn't mean there are no mixed breed breeders who are ethical, but you must carefully do your research to ensure you are not supporting a breeder who slaps a male and female together and hopes for the best.You asked why we want this in particular. We love the tricolor. And love the Bernese mountain dog but their life span is extremely short. And they are too big for our space. And poodle mix is great for being hypoallergenic and less shedding .. so it seemed like a great mix. If mixes of dogs are bad as you are suggesting.. I’m just not understanding why mixes of dogs at a shelter our different? I’m trying to understand. But yes.. I would love to find a local ethical breeder of what we like.
Mixes at shelters are sometimes the result of these unethical breeders, because unethical breeders don't take their dogs back if the owner doesn't work out. Sometimes mixes are strays, or just the victims of some unfortunate situation. They are not automatically worse than other dogs. Many good dogs come from shelters, but when you pay an adoption fee you're supporting people who help the dogs in these unfortunate situation.
With any "doodle", there is no guarantee that they are going to be less shedding or that they'll be hypoallergenic. Any breeder who claims so is likely an unethical breeder or has a misunderstanding of how genetics work, neither of which I would want to buy from! They are a mixed breed, and they could take on the genetics of either parent. If you need the less shedding traits of a poodle, just go with a purebred poodle.
But yes, do your research on what a good breeder looks like before you even start looking for breeders so you can spot the red flags right away. And you can always post here, we like helping to vet breeders, and sometimes someone might know of them!