Sure. It’s just extremely hard to get Constellations for them everybody wants to get new and flashier characters.
Amber is a viable DPS. Despite the fact that her scaling and damage multipliers are wack (seriously, Health Percent on your secondary Damage ability as a DPS?). I’ve seen some people hit for 30–50k charged shot on Amber. Of course, you’ll have to invest heavily into her. That was only possible because the Amber was crowned, and had a 5 star Bow. Realistically you can maybe hit for about 15–20k if you really invest in her.
Kaeya’s probably the best out of the three. He does basically everything. He is able to apply cryo, he’s sustainable because he can heal himself, his ascenion stat ensures that his ER is pretty good, and he does damage because he has good numbers. The same thing applies, you need to invest in him for him to be decent, every character does. It’s just that some characters need less investment for the same outcome.
I’m not too sure about Lisa. In terms of gameplay, she’s the least used out of the three. Her ascenion stat is EM, which would be great if she wasn’t an Electro character. Her E has the potential to do a ridiculous Damage, with 3 stacks, at rank 15, it has a 1200% Damage multiplier. However, that needs a lot of setup. Lisa’s entire kit is based around her being the DPS on the field. Her second ascension skill says that it reduces Defense, yet, the phrasing doesn’t specify if it reduces physical defense or elemental defense. If it’s the latter, she’s a great DPS character to use. I’ve seen some really dedicated Lisa mains put out big numbers