Agree, those ponchos are useless. Also, I find a need for waterproof trousers if just depending a standard rain jacket. I'm giving one of these a go this year, as another cheap option to hopefully be free of waterproof trousers and what that entails:
https://www.amazon.co.uk/dp/B00EPFX5A8?psc=1&ref=ppx_yo2ov_dt_b_product_details