Asbestos comes first
Sprayed acoustic texture applied before the early 1980s may contain asbestos, and that covers a substantial share of Orange County housing stock, particularly in Anaheim, Garden Grove, Westminster, Santa Ana, and the original parts of Lake Forest and Mission Viejo.
The only way to know is laboratory testing of a sample. If it tests positive, removal becomes licensed abatement work rather than a drywall job.
The removal itself
The texture is wetted so it softens and releases, then scraped. Wetting matters because dry scraping produces far more airborne dust.
The debris is heavy, wet, and goes everywhere in the room, so full floor and wall protection plus containment at every doorway is essential rather than optional.
The half people underestimate
Once the texture is off, the surface underneath is rarely presentable. It was never finished to be seen, because the popcorn was applied precisely to hide joints, fastener heads, and imperfections.
All of that now needs finishing. This is where most of the labour actually sits, and it is exactly what a suspiciously cheap quote is leaving out.
Smooth or retexture
Retexturing, usually knockdown, costs less because the new texture is forgiving of the surface underneath. Smooth requires a Level 5 finish and costs meaningfully more.
Both are legitimate. It mostly comes down to budget and how contemporary you want the room to read.
Go deeper