With the way how certain bots work, Webhooks wouldn't work with said bots. So my Suggestion is to include PubSub so more bots can utilize features like Hype Train and other stuff included on twitch.
Thanks for the feedback. This would most likely become a reality if/when we add a websockets transport to EventSub since Hype Train subscription events are already defined in EventSub. We briefly discuss how websockets could be a potential transport in the EventSub announcement if you're interested: https://blog.twitch.tv/en/2020/11/13/twitch-developer-day-2020-introducing-the-channel-points-api-eventsub-and-more/