If it is true that we are what we do, a corollary is that we do it with, to, for, by somebody else. As John Dunne said,
No man is an island entire of itself; every man
is a piece of the continent, a part of the main;
... any man's death diminishes me,
because I am involved in mankind...
The philosophizing recluse is an extreme, of which there are probably not many actual examples. More common are the professional or devoted amateur philosophers, who are narrowly focussed, and likely involved with other people who are similarly narrowly focussed. They occupy islands with a small number of inhabitants. Their "field" is very proscribed.
There are groups of extremophiles who are similar to philosophers: Old line socialists and anarchists come to mind. They are very narrow in their views, quite restricted in their activities. Actually there are quite a few 'specialties' in which a sort of OCD takes over, whether the subject matter is Jane Austin, bird watching, or body builders.
Most of these extremophiles are not harmful to society; they are more just irrelevant. I am thinking of actual people I know who fit as extremophiles. They are not bad people.
The really bad people in this world are immensely involved with other people as racketeers of various kinds -- Bernie Madoff to Mark Zuckerberg.
Most people fall in between the extremes, in the middle. Their lives are indifferent, good, or bad (a continuum) as they live out the roles, the possibilities, of their particular lives.
From my POV, the quality of a life is determined by what we do, with whom, to whom, by whom, for whom. Any individual on earth has opportunities to make positive contributions in their interactions with other people. Most people act in small positive ways most of the time. When large numbers of people act in negative ways, and larger negative ways at that, life for other people begins to deteriorate. Lots of examples of both the positive and the negative.