Backgrounds feature a connection, which is comprable to a bond. Destinies include a motivation, which is comprable to an ideal. The backgrounds also feature a heirloom which is sort of a tangible version of both.
Personality traits and flaws are basic characterization. I imagine players of a5e have built characters before.
Also, as mechanic which triggers inspiration, they just don't work. Part of Our goal was to replace the ideals bonds and flaws mechanic with something that actually worked for creating a mechanical incentive to role-play well.