Trumps decision to withdraw was conditional. As we’ve established he decided to withdraw from Syria and then reversed it following reassessment. Bidens decision was unconditional- he effectively ordered his military cut and run in the middle of the night leaving behind huge amounts of hardware, weapons, airbases that are now in the hands of a barbaric group. There’s a huge difference between the two, so yes it is his withdrawal decision.
As for speaking well, did you hear his speech last night? Stumbled his way through reading an autocue, then declined to answer reporters questions despite inviting them. Unsurprising given the gaffs he made last time he took their questions. He said x, y, z would never happen - then days later it did!
This isn’t an argument of who is a better president; neither are fit for different reasons in my opinion, but it’s inconceivable given the deterioration in his mind he can carry on for another 3 1/2 years. Democrats need to put party politics aside and work out a way to get him out of office given the number of serious foreign policy issues that are now going to crop up and will require dealing with as a result of his Afghan withdrawal one.