List of companies(with duplicates) with corresponding niche column.....

You can do it, as you have it, but it will be slow to calculate I'm afraid...

For info, where your criteria are defined strings you can use an inline array to shorten the formula, e.g. instead of:

Formula:

OR(A1="x",A1="y",A1="z",A1="apple",A1="banana")

you can use

Formula:

OR(A1={"x","y","z","apple","banana"})

however, it's no more efficient... and in your case, you would need to do some "chuntering" in the calc - i.e. multiply the OR by the test on Client, push all values into an collection and test sign of result.

it would, if possible, be much better to assign the category adjacent to the niche, thus negating the multiple OR requirements with a single additional test on category.

I've attached an example -- one new tab {Niche_Category}, and one new column on your developer tab {references Niche_Category table to assign value per Niche}

others will invariably provide you with an Array, or SUMPRODUCT type approach, but tbh I'd advise against that route, hence I've not provided the same.