A small change that I think would help a lot in this matter:
Split the last split in half with active users in the country.
(Ex from my country: Division III)
Those relegated from division II would be replaced only by teams from III.1 to III.8 (half of the division).
The relegated/bots from leagues III.1 to III.8 would be replaced by teams from III.9 to III.16 (the second half of the division).
Both following the same current criteria. No change.
In practice, it would be similar to creating a league for new users, who do not pay a minimum salary, to get acquainted with the game while playing matches only against peers and bots.
Consequently, it would improve the level of the last division with active users and,
mainly
would solve the problem raised here in this thread! =)