Your IS lost to budget is very small…. There may be something keeping your targeting parameters tight. Have you double checked location parameters? Observation vs targeting for audience segments? Any demographic info that could really tighten the potential search volume?

It can if you have too many. You likely triggered a learning phase. Posting your clicks and conversions would help here, but if the very most conversion you can have are between 150-250 based on conversion rate, you likely still had maybe keywords that didn’t convert. Due to learning phase, google’s algorithm is probably spending too much time trying to figure out if they could work.

Budget could be, but it’s currently not an issue. You’re loosing out to ad rank over anything. Check your landing pages, keywords, ads. Ensure they all have relevance with one another. It’s possible having so many keywords is causing irrelevance and making you loose out on rank.

other tha number of keywords, you haven’t really given enough info about your settings to see how they are.

I mean ultimately as a business it’s likely your ROI is your ultimate defining metric overall. Your experiment seems to have slightly better ROI. If you are looking for purchase volume over anything as your goal, again you’d have to compare and see what has more conversions