Tbh Djokovic's return game has declined significantly. He still hangs on by experience and his serve but he doesn't garner nearly as many breaks of serve or break opportunities as he used to. Per ATP stats past 52 weeks
Statistical measures of the best-performing players in three key categories in men's professional tennis.
www.atptour.com
1st serve return pts won - Alcaraz leads at 34.9%, then Baez! at 33.7% then Sinner at 33.4%. Djokovic is rated 13th there.
For second serve return pts % won, Sinner is king at over 58%! Djokovic at 53.2 comes in 9th for that stat.
In terms of % return games won, again Sinner leads at 33.3%, followed by Alcaraz, then Djokovic comes 9th at 26.5% so there's a clear gap.
If you change the filter to apply to only when playing against top 10 players, the differential becomes even more obvious (note of course the rating has limitations, some random names will have good stats at times - Vacherot leads this category filter

).
Djokovic also ranks #35 in the under pressure filter for break pts saved.