"Serverless"...this word is so thrown around nowadays that it lost its original meaning. Same way the phrase "we're like a family" transitioned from a beloved one in 50's to its thrown away in 90's meaningless all the way to today be considered a red flag when you hear such a word at a hiring interview, the "serverless" word is in its late 90's nowadays. One decade and will become just another red flag.
The meaning is pretty clear: you don't manage compute, it scales up elastically based on demand, even all the way to zero. Ideally, it reacts quickly enough to changes in demand that you don't need to worry about it. Serverless is basically the original promise of the cloud.
Take "OpenSearch Serverless" for example: They claim "you only pay for the resources consumed by the workload", but even if you have an OpenSearch Serverless collection you don't use, you pay at least ~$690/month (and that's not even accounting for stored data)!