I think most BIABs are being treated as a tougher gel base coat. A lot of clients now want the "natural nail life" so are using BIAB to grow their natural nails in a way that THEY believe is less damaging than acrylic.
Some BIABs are stronger than others. There's a very popular one out there that a lot of techs on Instagram use, I believe it's designed for overlays and tiny extensions (chipped natural nail repair, extending one nail shorter than the rest etc).
The BIAB I use is designed for salon length extensions using tips or sculpting forms. It can also be used for overlay when used with a rubber base coat.
The technique varies from brand to brand. For mine, cuticle prep, etch natural nail, scrub rubber base into the natural nail, cure, thin layer BIAB, cure, thick layer BIAB for structure, flip the hand over to level and form apex, cure, gel polish/topcoat.
BIAB should NOT be used on nails that don't need extra strength, despite some nail techs offering BIAB as there standard basecoat, with no softer alternative. Strong nails + Strong BIAB = hard nails that are prone to breakage/trauma when knocked. There's no flex.
I don't know which builder gel you use, so cant say whether a BIAB would be better, but if you have used the same product for years, maybe it's time to see what else it out there