What grade level should you write at?
There is no official grade target for the web. UK government guidance on plain English, and similar advice from many newsrooms, is to write so a busy reader can get the point on the first pass. In Flesch–Kincaid terms that often lands around grade 8–10 for public pages, and a little higher for specialist readers who already know the terms.
Do not chase a very low grade by breaking every idea into three-word sentences; that is tiring in a different way. Use the hard-sentence marks to find the lines that try to do too much, then cut or split those. If your readers are experts, a grade of 11 or 12 can be fine as long as the sentences stay under control.