Third party password managers are not necessarily reliable. Even the most respectable and well thought of has been breached. In addition, using another means providing some information to yet another source for potential attack. In today's environment of constant hacking and smacking, the less places one puts one's information, however little, is in my view, the better.

Cost is another issue, particularly with that awful and becoming ubiquitous move to subscription only products.

For anyone who doesn't want to pay for a reputable password manager but for some reason prefers a third party option, I'd suggest enpass - it's reliable and free and keeps ahead of potential issues.