Facebook page less active then before

Hello All, First off I am not an expert in social marketing hence I am posting this thread, So I have this facebook page which is for my Offline Store in a local city, When I had started the page/Business about 5 years ago, things on facebook was really good, like when I spent a set budget for the ads on a particular post I would get alot of responses and engagements and people were really engaged with the contents, But as years went by the engagement went down, the quality of content increased , but engagement decreased, meaning i had to spend like 3 or 4X my previous budget to get a fraction of engagement which I used to get, However during this there has been a local competitor who has been getting all my engagement (due to the similar name ) remember this competitor has just started with a similar name to ours (kinda copying) Anyways , so now they have surpassed in facebook page likes 2X of what we have on our page , their engagements on post are better and they spend so much less on ads ( confirmed with someone managing their pages ). what i don't get it what went wrong and how can this be over turned against them ? Any suggestion or anyone can provide solutions to this issue ? We have been losing a lot of money on ads with not much engagement (targeting and campaigns has been similar to what we have used before when we used to get a lot engagement ) .

Any suggestions will help alot