Most sites and web apps never even break a 100k/day hit mark for which I believe inefficiency may not be the biggest issue. But wasting a month tryig to write native Sql queries can hurt your project a lot more.
But that said... writing native SQL queries wastes a month? Um, no. ORMs are convenient, but writing select, insert, update, and delete queries by hand isn't that hard. It's mildly verbose and you end up repeating yourself lots so it's annoying, particularly if you (like me) have the kind of programmer's mind that constantly wants to factor that out. But it's doable without adding a high factor to development time.
Still, inefficiency is a huge issue. I need to be close to desktop-like performance for data entry, and that requiere both insert/read performance (that are executed in the same block and compromise several queries) below 1 seconds.
Request/seconds is not the metric that matter.
Is the seconds/for user(s) main activity.
Of course full page cache is the first stopgap for this problem but you'll always have dynamic content.
Unless it would be the first contact a developer has with SQL, I really don't see how difference in time taken to query the database with an ORM vs SQL would be anything more than a couple of minutes, maybe an hour if you really have a hard time with it or your data model is really convoluted.
I agree that 99% of all projects never push beyond what relational databases are capable of. I've seen developers who were tasked with writing basically a todo list say that they're going with a nosql database because RDBMs don't scale.
ORMs are not inherently inefficient. And in my time I have seen plenty of n+1 style queries written with raw SQL.
No they are not. Have you measured this in a real-world application? This overhead is negligible compared to the cost of the query itself. And without an ORM you still have to load the data into some kind of objects or data structures before you pass it to presentation, you will just have to write the code yourself.
But yeah, lazy loading in a loop will kill performance. So don't do that.
You may be able to write faster code, but unless you are Donald Knuth, you can't guarantee that any custom code you write will always be faster than some library.
In other words, you have no idea what you're talking about.
Could you please (re-)read https://news.ycombinator.com/newsguidelines.html and not use this site that way? The idea here is to post civilly and substantively, or not at all.