Finding a puppy is hard, @KingRoland. It's really hard. It's not just about finding a cute puppy online and thinking 'I want that one.' And finding a designer doodle that is well bred, is virtually impossible.
You are potentially giving someone £2000+. You are taking on a commitment that could live for 15 years. That is something that takes planning and care. And it takes trust. No one should be buying a puppy if they do not 100% trust the breeder, and no breeder should be selling a puppy if they do not trust the potential owner.
And, I cannot stress this strongly enough, no one should be buying any puppy that is not from fully health tested parents - not these days. Health tests are cheap as chips. The only reason people are not fully health testing the sire and dam is because they know their dogs are not healthy - and they know what the health tests would say. They know they should not be breeding from those dogs.
Buyers of these puppies make mistakes, and sometimes they get lucky but more often they do not and they and the dog suffer as a result. I know someone with a labradoodle that's a similar age to one of mine (not yet 3) and it can barely do a 15 minute walk without collapsing because its got such bad dysplasia as a result of dodgy breeding.
The thing with a good breeder, is that they will have poured their heart and soul into ensuring the puppies they are raising are happy, health and well-adjusted. That means long hours for eight weeks. It means constantly being present for those dogs. In some cases, breeders will have already started training your dog to be house-trained, or clean, or have taught them luring or basic commands. Puppy farmers, like the ones you have linked, do not do that. Partly because they do not care, and partly because they do not know enough about raising a healthy litter to even know where to begin. That is why good breeders will only have a litter every few years - because it's so damn hard - and why puppy farmers can have multiple breeding bitches, and litters, at once. Because proper breeders put in effort, and puppy farmers [like the ones you linked] do not - they just churn the puppies with little regard to those puppies lives. And you're not doing them a favour by 'buying the puppy to save them' no - people who do that support puppy farming.
And, lets not forget that even within breeds, temperament, energy levels, intelligence, coat density, form etc. all vary massively. No two dogs are the same. As @Ylvamoon says, the only real difference with a pedigree is you can be more confident in what you are getting. The problem when you start to mix breeds, is you cannot be sure what sort of personality traits you will get in that dog.
So, not only do you have a higher risk ending up with a defective, sickly, dog you also run a much higher risk of ending up with one with severe behavioural defects that most people are not equipped to deal with or manage.