whoever is using transaction fees as an excuse for not being consistent with his DCA is only trying to create excuses for himself and not looking for solutions to that short termed problem of transaction fee. Like you've said, the majority of us sometimes leaves our funds in exchanges for weeks pending when the fees will be more convininece for us before sending it out to a more secured wallet. It's not like you're unaware that it's unsafe to leave your funds in an exchange it's just the normal process you will get to experience as long as you're doing your DCA.
I think you are quite right, Transaction fees are not something that someone should take into account when they have implemented DCA. One reason I like DCA because we are consistent in routinely buying Bitcoin, regarding expensive withdrawal fees, of course there is an option to withdraw it once a month from the Exchange used.
DCA practice is very easy, only people find reasons for all ideas because they are inconsistent. If it has exceeded the 50th purchase, I think investors will not turn to other strategies. In the initial process, it is indeed very difficult, but if it is focused properly, our approach to Bitcoin cannot be separated anymore.
We are increasingly confident to continue buying even though the price is going up because the main principle of course to have Bitcoin is not in terms of its price. While there is time and while you still have a permanent job and while you have passive income, use the money to invest because at some point we don't know what will happen, but with our steps to invest in bitcoin, we have better savings that can be used someday or when we have reached retirement age.