Idk. It was the Yoshi/FE delays that make me a bit sore.
Going into more detail why I think it was a lackluster E3 among enthusiasts:
Smash looks pretty incredible. I do think they handled its presence in the direct poorly--a lot of what they highlighted was minutia better suited to Treehouse--and that combined with a content light direct gave the audience both bad pacing and disappointment. It probably also doesn't help that Ridley and Daisy (especially Daisy) were the only newcomers they showed off. This exacerbated the above issue.
But really the crux of the issue is, again, that Smash was made to fill such a big space when people were hungering for more.
The big announcements/surprises we got were leaked or 2019, e.g. Fortnite or DXM.
Limited third party announcements for Switch, particularly unexpected or 'big gets.' Doesn't instill confidence that Switch support is growing, which is something E3 could have done. Again, leaks don't help here.
The non-Smash/Pokemon Nintendo games we thought were most likely going to be unveiled (e.g. Yoshi/FE) were delayed and their showing was brief or non-existent. We got a Mario Party announcement, which isn't that splashy of an announcement though.
No outside hope possible 2019 Nintendo showings occurred (e.g. Metroid, Bayonetta, SMT, AC (?), 2D Mario/Maker (?), 2D Zelda (?)). Sure, there was no guarantee this sort of thing would show up but a) some 2019 content did show up and b) MP4 did show up last year.
Smash/Pokemon were already unveiled. Pokemon was already controversial here. Smash, again, was not shown well despite having plenty of exciting features.