Even if we grant your last claim, the question and acceptance of what is the most reasonable explanation – even far and away THE most reasonable – does not require absolute certainty. Accepting reasonable conclusions is done all the time by reasonable individuals.
N.T. Wright builds a case for the bodily resurrection of Jesus being, by far, the best explanation for the claims of the Gospels.
winteryknight.com/2015/08/21/n-t-wright-lectures-on-the-resurrection-of-jesus-did-jesus-rise-from-the-dead-5/
Here’s the thing…
Many will simply dismiss Wright’s set of arguments without reading them for the sake of hanging on to their own assumptions and prejudices vis a vis atheism. Yet, Wright is an individual who has spent the better part of his life studying the issue and has arrived at what he believes is the reasonable conclusion. Many, however, with much less warrant will dismiss Wright’s conclusion based upon a cursory and largely prejudiced reading – if they even take the time to give it serious consideration.
Radical skepticism gets us nowhere. At some point, life demands we make choices. Those choices can only be based upon sincere and sound reasoning – not absolute certainty, which isn’t available to us given that we are contingent beings with limited access to the full picture.
Jesus as myth is NOT a more reasonable or better reasoned position than accepting the veracity of the Gospels, it is simply a bland assertion of doubt for which NO reasoning is required, mere denial would suffice.
The problem with denial is that no one uses denial on its own to make progress in any endeavor.