Let’s address the dangers of mooring balls
There are several types of moorings but as you can see their maintenance status can vary.
1) Government Agency mandated moorings
these can be maintained by the government agency – state or municipality – or outsourced to a vendor so in countries where moorings are a mandate to use in a particular anchorage due to conservation or environment or safety concerns you may be forced to use them- the question is what happens if it breaks ?
Ideally cities and port districts also have established mooring maintenance requirements. The schedule to lift, inspect and (possibly) repair moorings vary from harbor to harbor, with many requiring renewal annually or every other year.

2) Private moorings or mooring fields
run maintained or operated by a marina or commercial entity –
Most likely they are not the same and the breaking strength will vary based on thickness weight and overall maintenance – the question is what happens if it breaks ? Who pays / what it is warranted for and since you are paying who actually warrants it ?
3) Individual locals moorings – small dive shop operators – fisherman – local guys who are not necessarily ensured – endorsed by the government agency to have them and are selling them to you anyhow – the question is what happens if it breaks ?
Material Fatigue
4) or bring your own mooring –
think YOUR ANCHOR – you set it you know it you add scope you sleep well