Eboost works well at low level as e shield isn’t as needed, but at higher levels I have found it better to invest some gold in sigils to slowly replace eboost so that way you can reinvest the energy boost skill points into either another DPS skill or into eshield, another lure, etc...
Oh.. I wasted all my skill points on eshield, and half on lure, max shards and i think some in eboost
Energy boost and shield are perfect for a low budget build. Inbetween about 60 and 180, you wont have that many skill points to spend, so if you have money and can axe some of that out, do so. But when you are endgame and have tons of bonus points, energy boost is great again(though with enough sigils, and ices slow cooldown, you could be in a situation to get some sigil ticks by nature just casting ice and refill that way).
Even at EG in a fire hotswap build I didn’t have enough points for eboost. Would have to choose between a half maxed shield or a half maxed eboost, chose shield every time.
Bolt, shards, AOE skill, DOT skill, Attune, Lure, and shield usually consumes all your skill points, especially at lower levels.
For leveling DOT isn’t useful for mages but even then, there isn’t much skill point gear available like at EG to make up for it.
Eboost is useful for low budget, but that doesn’t mean it’s better than other skills for DPS. Sigils can outdps eboost if you have enough of them assuming you use the eboost skill points for a DPS skill or 2