the lateral flow test is better than no test, but very prone to false positives, if you get a positive result you have to get the proper full test to confirm it!
My daughter works in the NHS as a midwife they are told to only do lateral flow test when on annual
leave (if at All!) because of the impact these false positives would have on staffing ,as the full test would have to be done to confirm the positive result.
Lateral flow is the cheaper quicker alternative test but comes with approx. 70 % accuracy.