It seems that Coinbase has been dealing with this issue for years now and it's quite surprising to see the platform hasn't been able to fix it. Is there a possibility for the exchange to be allowing or conducting these outages on purpose?
I doubt they're doing so on purpose most especially as they stand to benefit more each time there's an increase numbers of traffic on their site as a result of either people selling or buying bitcoin in their numbers. The funds this traffic will generate as a result of fees charge by the exchange is just something an exchange like coinbase won't want to miss.
And assuming this is discovered to be a foul play by the exchange, it will definitely ruins their reputation which I'm quite sure coinbase won't want to risk that happening. A big exchange like coinbase though should have been able to tackle this issue but don't get why that's not the case.
Issue like this experience repeatedly by other so called reputed top exchanges is why we have to give credit to Binance for been ahead of the games. Assuming such issue was experience by Binance, they would had done sometime immediately to prevent the site from experiencing similar issues.