Yes, and in 2021 crypto was in a much better state and SPL was completely different from where it is now. With reward cards not being SB and bots allowed in modern they were able to pay for the 20 spellbooks and get ROI rather quickly. Since the drop in crypto and the changes to rewards and bots only allowed in wild, I would agree that a bot account getting its ROI is easily 2 years.
I use to play in gold and would rent the remaining cp to push into diamond on a few occasions, this to me was the most enjoyable time in SPL. After the CP/SPS change my rating per win plummeted and since then ive had to drop to silver, getting 40 EOS silver chests and 4+ daily chests are better than 10 EOS gold and maybe 1 daily imo.
I feel that the current bot measures have done enough to curb bot farms of the past, and creating new ones aren't profitable enough to bother with.