Short answer: Yes, absolutely. Garrett is still firmly in the top tier of fantasy defensive ends for 2026.
He's coming off a historic 2025 season — 23 sacks, a single-season NFL record — and the wiki notes he "remains an elite pass rusher who transforms any defense he joins" (from the Myles Garrett page). The move to LA actually helps his production outlook: he'll line up next to Chris Jones on the interior, meaning fewer double teams, and the Rams upgraded the secondary (traded for McDuffie, signed Jaylen Watson), giving him extra time to get home.
At 31, elite edge rushers can absolutely still produce — and Garrett is a freak even among them. The only caveat: make sure your league uses IDP scoring. If it's a standard league that doesn't start defensive linemen individually, this doesn't apply.