Checked and it behaves the same in Safari as Chrome so it appears this is left over from WebKit and by HN logic since Apple did it it's the right way! (jk) Yes

Checked and it behaves the same in Safari as Chrome so it appears this is left over from WebKit and by HN logic since Apple did it it's the right way! (jk) Yes, I agree it should be fixed. Most WYSIWYG editors do have issues though. Just tried Pages (apple's word processor. abc <b>def</b>. Putting the cursor before after the space before the d I would personally think is more intuitive to insert bold but it inserts plain. As it is there is no way to type bold at the front of the bolded word. You either have to type new text and bold it OR you have to insert after the d, type a new text and an extra d then delete the leading d. Yes you can press Cmd-B then type but of course if the text had more styling applied that would get cumbersome to reapply styling so you're left with the previous solution of inserting new text in the middle and deleting the leading character.