Because removing Trump wouldn't save their seats?
The people that want Trump out aren't voting Republican regardless. They are going to try to max out the votes from the GOP base and try to make sure they don't get primaried by angry MAGA voters.
This is about money.. Trump is raising money for himself and his defense, he’s not spending it on GOP incumbents.. The same gop incumbents who are losing the fund raising battle to their challengers for their seats.. It’s every man for themselves in the GOP at this point.. They will absolutely throw trump off a cliff if they can make a deal to get pence to fill the POTUS seat..