Here's some resources that I use often:
- mtggoldfish has meta decks and user submitted decks for almost all popular formats out there. They include a meta % to show how much a deck is played.
- for more competitive meta results I use mtgdecks.net, where you can filter on recent tournaments or MTGO leagues within the format you're interested in.
- lastly there's aetherhub, which I use less these days but is also a good source for meta deck finding.
- if you're looking for meta discussions and deck techs, you can still find them on reddit, e.g. the /r/spikes subreddit or the subreddit for the format of your choice, for Pioneer there's /r/PioneerMTG