There's how you think you'll react, then there's how you actually react. Not always the same thing.
Absolutely.
Incorrect self-assessment of capability is a leading factor in many diving accidents, solo or otherwise. It's particularly pertinent to solo diving though, as there'll be nobody around to save you when the flawed assumption presents itself.
Intermediate level divers
tend to have a false confidence in their ability. That false confidence tends to establish itself as a result of increasing experience that is limited to 'best case scenario' outcomes. i.e. they do a lot of dives, but nothing goes wrong. Thus, any self-assessment is based upon a notion that "
I've done XXX dives and never had a problem, I must be good". That is a flawed assessment of ability.
The situation is confounded by the focus of basic scuba courses - where training is deliberately made easy, simple, convenient and low stress for the student. Most novice divers are unaware of how undemanding that training is, compared to the reality of a 'real' incident response. The training aims to make them 'feel' confident in their abilities - and it succeeds. It is then reinforced on subsequent dives, because nothing happens to go wrong - those weak skills are not put to the test. The only safeguard against this
confidence vs. capability miss-match is the imposition of a defined set of 'recommendations' which limit the challenges and risks of their diving. In this case, the reliance on the buddy system for safety.
Those divers with a substantial amount of experience (enough experience to have encountered a few 'worst-case scenarios'), or those who have taken advanced/technical level training courses, will have been exposed to
a more realistic focus of training. Divers, at this level, aren't encouraged or pampered - they are tested and challenged. Very few, if any, intermediate to advanced level divers come away from such training, or incidents, with a perception that they are 'good' divers. It is typically a humbling experience.
A well-run Solo Diving course fits the definition of 'challenging'.
So, having been coaxed and encouraged through a kindergarten-like scuba training syllabus...and having done a bunch of undemanding, incident-free dives, is a diver really positioned to make a decision that they are now capable of shrugging off their one true safeguard against the potentially lethal consequences of making an error, or not being able to deal with problems that may arise?
Harking back to my first post in this thread, I see that there's already a host of divers who somehow feel qualified and competent to encourage an unknown internet stranger to disregard the safety advice linked to their qualification and experience. That's a bold step - and I am still at a complete loss in figuring out how these people can give such advice without ever having met the diver concerned, or seen them perform on a dive and in response to a problem.
Suitability for safe solo diving is an individual, unique issue. The competency of the individual, their physical and psychological make-up, their performance under stress, their problem solving ability, their reaction to panic... are all factors that need to be considered
before encouragement to abandon the life-line buddy system is advised.