Do you have any suggestions I might pass on?
Let's say I need data analysis. Thousands of companies can service this need. Very few have the specific certification for the fed agency/state/municipal requirements du jour. I have no solid way of searching all holders of all these certifications by service line.
So, I search online, I call peers, I dredge for vendors. Vendors who approach me and can quickly communicate their contract value with small business/minority-owned/women-owned whatever, and can demonstrate their knowledge of the particular market the RFP is for means they know and are ready to be added to a larger RFP and can document their claims.
For me, this saves me time and money, and brings value.
I could see some small cases where the government would restrict the size of the company responding to an RFP, but there are also ways around that. The small business can contact the contracting office and protest saying they were unfairly considered for that acquisition and usually will win.
The key to the Federal Acquisition Regulations (FAR) is that they try in earnest to support and encourage fairness when awarding contracts. Furthermore, the government goes out of its way to give the "underdog" a better-than-equal chance at winning the contract.
As another poster said, the small business can't lose out on other reasons (i.e. certifications, financials, etc). It could be that they're losing contracts for very different reasons.
Here are some links for reference:
SBA size standards: https://www.sba.gov/content/small-business-size-standards
GSA Small businesses: http://www.gsa.gov/portal/content/202261
Small business set asides: https://www.acquisition.gov/?q=browse/far/19/5&searchTerms=s...
Protests: https://www.acquisition.gov/sites/default/files/current/far/...
They aren't required, but not doing so will necessitate a good justification. The Small Disadvantaged Business (SDB) designation is basically an automatic justification, but not the only one. Contractor past performance, the reasonableness of the bid, and other considerations can drive the government to actually choose a higher bidder. It also matters whether Widget is off-the-shelf or bespoke; the contracting officer tends to get more discretion in the latter case.