Disagree with that, he'll get other jobs after Barcelona (unless he somehow gets worse next season and there is a 30 point gap between them and Real Madrid in the league)
Lampard's issue is that it was too much too soon for him and I never really saw him as being a great tactician from his playing days. It's not like Pep, Arteta, Alonso at Leverkusen, you could see from their playing days that they would eventually coach at some point in their careers. The same can probably be said about JT, Thiago Silva....I just see them as coaches at some point in the future (whether they want to be the first team manager is a whole different question but both of them could walk into assistant coach roles).