There is a huge difference. They can both say they were in a relegation fight when they got here, because it was a fact.
Dyche constantly talked about changing the narrative, but when he improved on the points total in his second year, got far more players and time than Lampard got to put his own stamp on things he completely gave up the changing of the narrative and decided to reinforce the narrative this season by telling his players they're crap and belong in a relegation scrap. Because he belongs in a relegation scrap, it's where he is at home.
He also acts like he's seen it all and knows it all and doesn't take responsibilty, but Lampard acknowledged he had a lot to learn and often took responsibility. People respond to things like that, I know I do. Lampard is just far more likeable than Dyche and liked and respected the fans way more than Dyche does.
Dyche did his job, not saying he didn't, it doesn't make him more likeable though. Now he's going backwards and doesn't care about 'the narrative', the fans or the club, just his own rep.