The headline amount and the withdrawal cap pull in opposite directions. The offer that looks smaller is often the one that pays more.
Offer A gives 1,000 in bonus credit with a withdrawal cap of 500. Offer B gives 368 with a cap of 1,500. On the banner, A looks nearly three times as good.
A withdrawal cap is the most you can take out from winnings made with the bonus. Under offer A the best possible outcome is 500, no matter how the play goes. Under offer B the best outcome is 1,500.
The other condition is how much must be bet before anything can be withdrawn. A larger bonus with the same multiple means more turnover and therefore more expected loss along the way. See the arithmetic in the note on margins: every bet carries a cost.
An offer is only as good as the smallest of those three.
This exact pair of offers is analysed in a Traditional Chinese forum post comparing a 1,000 bonus capped at 500 with a 368 bonus capped at 1,500 (送1,000上限500 vs 送368上限1,500). The conclusion matches the reasoning above: read the cap before the headline.