It would not make sense to create a fast open source miner, other one will take this code and make his own miner with a devfee, this is how the world works, sadly for sure.
And in my case, i have no problem to pay a devfee for all the work, but some miner devs take a very high devfee for some algos. I mean all over 2% is too much in my opinion.
But i agree with you, community projects are not seen anymore.
And now you should not even run a proven miner on the main computer for safety. For this, there are good operating systems for mining or separate mining farms.
I think it is the developers who ask a fee for their product and there is nothing wrong with that.Usually they run a batch script in Windows and a script in Linux where we can see all the configuration and the well known software makers make really good miners,the fact that we pay 0.5 to 2% is the least of concern for me if the miner proves its stability.
The best thing to do as noted is to keep the wallets if you don't use hardware wallets,keep those desktop wallets in a separate PC which is only made and created to hold your coins.Of course if a free miner offers the same performance as a "paid" miner I would still choose to get the support of the guys who consistently look after their product and solve arising problems (Claymore is an isolated case).