I doubt it very much.
The MC didn't have to kill much and absorb Qi in these months to already qualify as one of the strongest Houtians.
Let's assume that, even though the difficulty of advancing gradually increases, with each advance his strength grows exponentially, in which case killing will be easier and easier, the gains will be greater and greater, etc.
I believe that less than 20 years will be enough. The same goes for Ruo (I still don't know how), after all he is, narratively, the rival.
Not to mention that Tang Yichen is probably one of the "bosses" that the MC has to face, and the way the other characters describe him, as an old man on the verge of death, I don't believe he's older than fifty. (Just to be clear, this last paragraph is pure opinion, unlike the others, after all, I don't have many arguments to back it up)