If broadcasting a transaction from a solved Bitcoin puzzle gets hijacked instantly by bots, does that mean all transactions spending from solved puzzles were mined directly ? And if the publick keys to certain puzzle addresses are already exposed publicly, why haven’t the bots swept those funds yet, if they claim they can steal coins within seconds?
You have some conceptual errors about the problem:
With the public keys exposed, you can't move funds ---> You need to calculate the private key, currently puzzle 135 and multiples of 5 and up. ---> Use the polling kangaroo algorithm, etc.
Bots can attack the PVKs of smaller puzzles, currently 71 and up, since it computationally leaves a window.
In my humble opinion, small players currently have no chance.
A large player who finds puzzle 71 will look for a very secure way to propagate, obviously avoiding the mempool.