Prayer, like many rituals, is something that the religious get some real benefits from that are just lost to us heathens. One reason is that many of these rituals are performed communally, as part of a regular meeting or worship. This means there is social reinforcement. But the main one is that the religious context transforms them from something optional and arbitrary into something necessary and grounded. Because the rituals are a duty to our absolute sovereign, there is strong reason to keep them up. You pray every day because you sense you really ought to, and it will be noticed if you don’t. In contrast, the belief that daily meditation is beneficial motivates in much the same way as the thought that eating more vegetables or exercising is. Inclination comes and goes and needs to be constantly renewed.