It was pouring rain today, but even the downpour couldn’t stop my maternal
grandparents from joining us for their Mother’s Day celebration at a restaurant.
I swear, their go-to move is always eating out—it’s such a cliché! Haven’t they
ever considered hosting a gathering instead? Then again, Mom’s foodie gene
definitely comes from them. She’s not even supposed to be eating solid food yet.
But of course, she ignored my advice. And just as I predicted, they spent way
more time chatting than actually eating. By the end, I was practically nodding
off at the table.
So instead of saying pouring rain we might say pouring down rain to emphasize the amount of rain that's coming down and it's raining very very heavily otherwise pouring rain is fine..
Mother's Day celebration at a restaurant.. usually we would either name the restaurant like mother's Day celebration at jollibee's or mother's Day celebration at Texas Roadhouse steakhouse, but after times we would just say something to make it feel more specific so it would be their favorite restaurant instead of a restaurant a restaurant makes it sound like it's just some random choice, their favorite restaurant or the restaurant around the corner from their house. The restaurant where they first met. Something like that. Makes for better storing telling and it just sounds better. Grammatically what you wrote was fine.
"hosting a gathering instead" ? Where?
So generally speaking if you're hosting a gathering you don't do it at home so why would that be any different than getting together at a restaurant? Or maybe this is something that being lost cross-culturally I'm not quite getting what you mean why that would be better than just going to the restaurant? Because for me as an American those are basically the same thing unless you're doing it at home But then you would say "hosting a gathering at home"
There's not anything wrong with the grammar just feels like things are missing.