Poor 5G speeds

Poor 5G speed. I have been on Rain 5G now for the last 2 years and it seems like they are now just taking for granted the customers that joined them when they had a few. My speeds have dropped from 200+ mb p/s to 20-60 mb p/s. I am so frustrated due to the fact that I have fibre available at my house which I can get twice the speeds at the same price as what I am paying for my 5g. I have tried moving my router even set up outside my signal strength is a 9.5 out of 10 but still the slow speeds. Can you guys fix this or should I rather move over to Fibre connection?