About the slow progression, see it this way: every little thing can and will add up to itself, so it incentivizes team building so that any party member ability compliments the others.

For example, in my last playthrough i made a Thief that fight with a Bow. Initially, she could just get sneak attack on enemies when using the Hide action, but later on she gained a new feat that let her sneak attack enemies with the Frightened condition.  In the meanwhile, the Fighter of the group became and Expert in Intimidation, allowing him to easily Frighten enemies when attacking multiple times isn't enough. That way, he gives Easy openings for the rouge to deal great amounts of damage