I'm Blue daba dee daba die wrote: Shockwave generation, BFR, and light blasts
shock waves can be countered the same way punches are, light blasts might blind thanos but its not a wincon, and goku only goes for bfr when he has no other option, where as thano's first move is to use the reality stone which goku doesnt resist + thanos has the space stone and can just teleport back.
thanos uses the power stone to counter ki, punches, shock waves and potentially light, and he uses the space stone to counter the BFR. (so actually leaving all but the power stone might have been the least fair.)
But Thanos always goes for the incap shot at the very least. Goku doesn't know he's a villain so he has no reasons to go full hitman on this one.
Goku also has no reason to hold back or even try to play with Thanos. There has been flat 0 instances of Goku ever going easy on an opponent of equal, especially with Thanos being capable of outputting 5 Ninatons of TNT.
Along with that, SBA makes Goku willing to kill which he isn't normally. A Willing to Kill Goku is more in line with what we see SS Goku as; namely ruthlessly beating the opponent up no-bars held and only showing mercy near the end, which even then he's still liable to just blast you.
Goku legit does not need to know he's a villain, by default, making Goku willing to kill means he's lost the thing that makes him "nice", that he doesn't kill people unless absolutely neccessary.
This is also assuming Thanos himself isn't liable to go into a speil on how he will wipe away half of all life in the Universe, especially if Goku opens with a "Hi". Thanos as we've seen him in IW is straight up never going to just smack Goku in the face mid-sentence. In fact, small talk is a fairly common thing he does.