I only watched the first season of Picard (and, sadly, didn't like it much), but I got the impression that Stewart was acting feeble. I saw him on TV a few times (Graham Norton, the Oscars, maybe something else) around that time, and he looked and moved way better than he did in the show.

I watched "Boston Legal" because of him. He clearly was enjoying himself, including making snide remarks about himself and making references to Star Trek. I wish him many more happy years.