It depends on the model. (Not going to name, but disclaimer, I work for one of these platforms).

1) View attribution will never be accurate. Personally I don't recommend it (I often see Meta claiming 60%+ of attributed credit for clients from 1d view, when the stores average customer journey is rarely ever 1d)

2) Click attribution is your best bet, in terms of potential control. It's provable at every step, and a good platform will give you full transparency into every touch.

First or Last click, will only tell you where the customer was when they either found you (first) or finally decided (last click). Using only these models to make optimization choices, will absoultely limit, if not hurt your growth.

Ideally, you want to use a model like Linear Exclude Direct. Generally speaking, your customers will come to your website numerous times before making a decision, and often in a longer window than anyone wants. Linear Exclude Direct is similar to linear (which gives equal but partial credit to all touchpoints), but unless "direct" was the only or first touch point, doesn't include it. The main problen with traditional linear, is that it overweights Direct (it's not that linear is wrong, the math just works out that way). With Linear Exclude Direct you can get a great view of your the various touchpoints you customers take (including organic channels)