I'm a few months away from being 40, and the common trait amongst the 40+ crowd is people and leadership skills. Management is the common track that people take, but you can be a technical leader if the company needs it (I'd argue most companies need them, but many companies don't manage tech itself).
Yes. By that age people getting tired of "being managed".
Large companies have more management positions though. What should someone 40+ do at a small firm? Start again at BIG Co as developer and wait 5-10 years to become manager or tech lead? Is that the only option? Can we say 40+ developers at small companies are mostly buried without carrier path? (I think it can be the case for many.)