Caustic is a more offensive and versatile legend than Gibraltar. Why? Because of his tactical ability. The only way for Gibraltar to be offensive is by waiting for his ultimate to charge "and by the time it’s ready, you’re probably already back in the lobby" and being in an open space. Caustic’s ultimate can be used both indoors and outdoors where it’s even more effective and his tactical can deal damage in any way.
Caustic is better in the early game, while Gibraltar performs better during the final moments of a match.
You're right facing an Ash is almost always a losing battle. She has everything: damage, evasion, speed, escape tools, and the ability to chase you down. Honestly, I hate that legend, but I don't mind if she stays the way she is.
However, something needs to be done to make other legends more viable.
What changes do you think could make Caustic a better legend? I’d love to hear your ideas.
For example, I have an interesting idea for Gibraltar:
What if his Dome Shield converted the damage it absorbs "from bullets, grenades, or enemy abilities" into a temporary shield boost for teammates inside the dome?. A bar would appear, granting bonus shield for a limited time, depending on the amount of damage absorbed and the duration/impact frequency within a mid-range window.
EA_Mako