When you IPO you sell a (usually) significant percentage (generally from 20% to 80%) of your company for an opening price - you don't get to capitalize on the h

When you IPO you sell a (usually) significant percentage (generally from 20% to 80%) of your company for an opening price - you don't get to capitalize on the hoped-for increase except with the percentage you didn't sell, either personally or corporately, as there are usually many limitations to discourage loss of the established personnel to sudden wealth syndrome. In the SPAC (and similar) models, you "sell" 20% of your company for a fixed amount (in exchange for the SPAC's cash). The remainder is yours to nurture as needed. With a little planning you avoid a lot of work generally irrelevant to your core business by finding an available company to be acquired by and who is by experience a good partner for publicly traded relationships.