Creating a multi-account for the sake of welcome bonuses is a pointless idea, because, as you said, almost all gambling platforms set wagering requirements for bonuses, and as a rule, these requirements are too high, which makes the pursuit of bonuses pointless both for the average user and for the avid abuser who has many accounts.
Right, trying to benefit from casino bonus programs is a difficult matter, especially creating additional accounts for this. Except that it gives pleasure to some players when bonuses create a feeling of freebies and the opportunity to play for money without investments. But this is all an illusion and there is no point in it, it is better to take some money from your savings and play without the need to wager the deposit.