The form is the easy part
Almost every marketing site can capture an email address. That problem was solved a decade ago.
What breaks is everything downstream. The submission emails a shared inbox. Someone sees it that afternoon, or the next morning, or after the weekend. By the time anyone replies, the buyer has already talked to two competitors.
Then there is the quieter failure. The lead arrives with no idea where it came from. The campaign that produced it is not attached to the record, so the next budget conversation is a guess dressed up as a report.
A form that collects is not a pipeline. It is a to-do list nobody owns.