Yep probably, or maybe apple just want us to purchase more cloud storage
How does deleting files from your local HDD affect the amount of cloud storage you use?
The amount of cloud storage doesn't change, whether you keep a copy of everything on your HDD, or whether you keep just a few documents locally. Every cloud service has you keeping everything in the cloud, with some variation on whether you store copies on your local device, or not, and to what degree.
Sure, Apple, Google, DropBox, etc. all want to sell you more cloud storage. However, the particular feature we're discussing (managing the amount of cloud-stored data duplicated on a local device) exists to reduce the cost of the
local device, specifically Flash storage-equipped mobile devices and computers.
A $1/month (US) 50 GB storage plan (costing $36 over a three-year period) can help a person avoid a $100 storage capacity bump-up on their iPhone. Even the $3/month 200 GB plan delivers a break-even over three years. And increasing the storage to a higher tier when it fills may still be cheaper than buying a new, higher-capacity iPhone now, rather than continuing to use the same phone for another year or more. Arguably, if people are keeping their smartphones longer, the availability of comparatively inexpensive cloud storage may be one of the reasons. In that case, Apple may be doing themselves more harm than good.
Although the price of Flash will inevitably fall, its higher cost (relative to HDDs) has disrupted the price/capacity status quo in PCs. Historically, there's been no price penalty paid for doubling the amount of internal storage with each replacement PC - The price-per-byte of HDD storage tended to drop faster than the replacement cycle of a PC. People moved the contents of a full 250 GB HDD-equipped PC to a new, 500 GB HDD-equipped PC. When that filled up, they moved to a 1 TB HDD-equipped PC... but then how could they
affordably move from that to a 2 TB SSD-equipped PC? It's very likely that the cost of Flash is the reason you need to manage the number of files you keep on your local PC.
But getting back to your original question... If you prefer the way Google allows you to manage local storage, by all means, use it. It's not a matter of "better" or "worse," because each user has their own idea of what's optimal. I happen to like Apple's automatic management. That's why we have choices.
Historically, all cloud storage services began by caching the entire contents of your cloud account on your PC/mobile devices. The theory was, everyone wanted access to all files all the time, even when they lacked an Internet connection. That's changed over the years - the more we put in the cloud, the higher the price of carrying around a duplicate of it on our mobile devices and PCs, and the more we realized 24/7 access may not be essential for
everything.