I also disliked Sebastian Vettel in his Red Bull days but since joining Aston Martin he has probably become the main driver I support in Formula 1 along with Mick Schumacher. Mainly because, as I said, he is the most passionate F1 fan of the drivers.
Whether or not he is an all-time great I think depends on how many drivers you classify as all-time greats. I would not put him among the top 10 greatest drivers of all time, but I would put him in the top 15, which I think is enough.
Also these deserve mentions for classic Vettel:
https://www.youtube.com/watch?v=FlFt_W4664M
https://www.youtube.com/watch?v=9ECeVacI5Bc