I see. I was previously at a company with PTO and when I left I was paid the balance. At my new company I have both, but unless I use sick time basically as '2nd vacation pool' (potential ethical issues etc) I actually end up with less time off.
As a corollary, if you have PTO and intend to leave a company, use it up before giving notice.
And we haven't even touched on other issues. People with PTO may be less likely to stay home when they are sick, because it reduces the amount of planned leave they can take. This results in more contagion in the workforce.
There are very good reasons for paid vacation and paid sick leave to be different classes of benefit. But in this case, it is simply a coal miner's canary. A company transitioning to PTO is reducing their labor costs by reducing the benefits of their productive employees. Look carefully to determine whether any effort has been made to reduce overhead. PTO by itself is not an unambiguous signal. If execs are still giving themselves bonuses while your earned leave becomes PTO, they probably just reassigned the value of your benefit to themselves, and it's time to look for a new employer before they come up with another bright idea, like stack ranking.
This criticism also applies to some extent to "we don't worry about leave" companies. I haven't ever worked for one, so I can't say for certain.