Well, Seth's answer is the right one, but no one has fun with that.
![Smile [smile]](https://www.festoolownersgroup.com/Smileys/default/smile.gif)
I would add a persons "history" a big factor. Those who bought tools that ended up with abandon'd battery systems tend to be much more careful about going cordless. If you had tools from the major players in their early system that are no more, it will always be in your mind.
I own a lot of battery tools, but they are also part of what is probably the biggest cordless system out there. The cost of most the tools means if in the future it goes away, and someday even the biggest battery system will get replaced with something else, the price hit won't be that bad. At the same time, that system has some tools that cost thousands of dollars (they just launched on that is over 9000 USD, but even more conventional stuff can be 2000-6000USD), you don't want to get stuck with that when the system goes away.
Things have been stable around 18V tool systems for a while. But as Cordless chop saws, table saws, routers, chainsaws, yard tools, etc become a thing, there will be a bigger system out there by companies, then folks are going to start to worry how long the stuff they have, has.
Ideal world, there would be a couple size batteries, all built to a universal standard, so most the concerns go away. But that isn't happening. You will have small players get together to pretend they are some standard battery system, but it's not going to change the reality that the big players will have their own setups.
Festools cordless stuff isn't pointless, but it will always suffer in that Festool will never have the full array of tools of a big red or big yellow. That will always make the buying decision more complicated for professionals or individuals no matter how they use them verses other brands. There is no one answer for what folks will do/want.