In 2019 he won 1 atp1000 and 3 atp500, it was not a disaster but neither a memorable season.
Every tennis fan shall remember Wimb.'19 F for the rest of their life, much more than Connors' great USO'91 SF.
In his last eight seasons Connors has won 4 titles, 0,0,0,2,2,0,0,0 respectively, finishing as no. 49 and 84 in the last two (1991 & '92) after skipped 1990.
75 % fit 39/40 y.o. Federer would still win at least couple of 250/500 tournaments and probably called it a career if he were out of top-10 for two consecutive seasons without slam SF and masters title, and also probably rejecting a lot of money from sponsors and tournaments for appearance therein.
He could probably get a WC for almost every slam and masters (if he were out of top 100 after an injury, without protected rankings) + 5-10 million bucks (endorsement + sponsors) for just a few rounds passed therein, at quite a few of them.