Your bio is read at exactly one moment: after somebody likes an item and before they pay. They are asking whether you will still be here in six months.
Say what you build, specifically
"We create high quality premium solutions" describes every store on the marketplace. "I build booking and scheduling systems for service businesses, mostly in Laravel" tells a buyer whether you are the right person for their problem.
Say how long you have done it
Not to boast, to reassure. "Eight years building this kind of thing" answers the question they are actually asking, which is whether you know what you are doing.
Say how you handle support
One line. "I answer support requests within a working day, Monday to Friday." That single sentence does more for conversion than any adjective, because it sets an expectation you can meet rather than an impression you cannot.
Be a person
Stores that write as "we" while clearly being one developer read as evasive. A named human who takes responsibility is more reassuring than an imaginary company.
What to leave out
Mission statements, a list of every technology you have touched, and anything about passion. Buyers are not hiring you, they are deciding whether your item is safe to depend on.
