I do participate from time to time in deposit bonuses as it can be interesting depending on the wagering requirement. Sometimes it is 30x and while that is still extremely hard to do, it is possible to do. Best bonuses for me are like weekly or monthly bonuses without any wagering requirement.
Weekly or monthly bonuses comes without wagering requirement because most of them are basically a rakeback from your previous week/month wagering activity. The more wager you did, the higher bonus you'll get unless the casino use fixed amount for the bonus. Weekly and monthly bonus become a trend since Stake introduced it and maybe Stake is the first casino provide weekly and monthly bonus. After that some other casinos are following this type of promotion.