You don’t need to go through some form of auth now, or use webhooks. The main differences are that the client id has to be in the header of the request now, and if you’re looking for data on multiple channels instead of doing &channel=CHANNEL1,CHANNEL2,CHANNEL3 you would need to do &user_login=CHANNEL1&user_login=CHANNEL2&user_login=CHANNEL3 etc…
Helix also has rate limits, which means you can make 30 requests per min if you use just your client-id, but if you use an app token your limit would be 120 a min, but again that’s not a requirement, you can do it entirely without authentication on that endpoint if you choose.