The laws of Tashlumin (making up for prayers unavoidably missed) are delineated in Halachipedia
“If one forgot to say Shacharit one should say Mincha twice, the first for Mincha and the second as a makeup (Tashlumin) of Shacharit.” Etc.
To whom are we “making up” when we do tashlumin? I find it difficult to think that HaShem is so to speak missing that prayer.
Should we think rather that our Rabbis gave us the opportunity to make up for the lost opportunity to make a connection to HaShem?