You may be asking yourself why all those not surnamed Trump are still in the race for the Republican nomination? So far only one has dropped out. I have zero insider information but here is my best guess.
If a Democrat President, Democrat Attorney General, and generally Democrat federal bureaucracy cannot manage to convict Trump of something, they are even more feckless than even we choose to believe. Out of four indictments, with possibly more to come, and literally dozens of counts charged, odds are great some of that will stick, especially with a jury in DC that will be mostly or entirely Democrats.
When that happens, we are in uncharted territory. Will the Republican establishment, in the guise of the RNC, decide a convicted felon appealing his conviction cannot be the party's candidate? That is certainly a distinct possibility. Or the party's voters may decide something similar.
With Trump out of contention, a Republican who has campaigned for it has a distinct chance of becoming the nominee. Whether that nomination would have value is anybody's guess, my guess is that it would. Biden's unpopularity suggests nearly any of the non-Trump Republicans could defeat him. So expect them to stay in the race if their money can be made to last, while they wait for lightning to strike Trump.