Instead they insult their employees with ping-pong tables and snacks and Xbox.
Even the famous "unlimited vacation" is a complete and utter scam to shame and guilt people and also to avoid having to pay for accrued vacation time that normally you would be entitled to.
Some even list their garbage noisy open office as a "perk". Yeah Bob it's a great perk for employees to have to use noise cancelling headphones to get their work done while everyone "collaborates" about TV shows.
First they pick something that benefits them, then they reverse engineer some kind of happy story about how it's really a perk for their employees ... let's save some money on office space because .. uhhh ... "collaboration!" yeah that's right ... SO GOOD!
Let's save more ... you don't really need that desk all the time eh? HOT DESKING. So HOT! So FLEXIBLE! you're welcome.
Vacation? easy! unlimited! just take "what you need" wink wink (http://archive.is/ByJ8X)
The situation has turned so bad that even the very basics can be considered perks.
Like .. uh ... a quiet fucking office with some sunlight, you know ... for getting work done?
If they were actually interested they could offer lots of genuine perks.
For example one week extra holiday on top of what the minimum is (government requires 4 weeks? offer minimum 5 weeks in good faith)
Another one, establish and enforce a culture of not working overtime. For example if everyone is working 9 to 5 at a company, have a culture of kicking everyone out and shutting down at 5 unless in very very exceptional cases.
Wanna go further? Make remote a thing. For example if it's a traditional Mon-Fri 9-5 shop, establish remote Wednesdays for anyone who wants it.
Another one? Reduce work hours by 1 hour every day. Instead of 9-5 make 9-4 the standard in your company.
Wanna show you really mean it with the perks? Keep the market salaries and make the work week 4 days. Anyone fortunate enough to work for your company gets Wednesdays off.
Admittedly some of those are quite bold but I think they only sound so bold because no one is even trying to actually offer tangible perks. Many companies have enough fat that they could afford it.