As we count down to Apple's big iPhone event on Wednesday, the tech universe is abuzz in what new devices and features Apple will unveil to the public.

All the leaks making their way to the public about the new iPhone 6S and iPhone 6S Plus sound great with one exception: Device storage. If rumors are to be believed, Apple will continue to offer the iPhone 6S and the iPhone 6S Plus with a entry-level storage capacity of just 16GB.

If true, this is a huge disappointment. 

In late 2015, the time for flagship phones with 16GB of storage has passed. It's no longer acceptable to offer phones with only 16GB of storage. It's just not.

We may be moving to a cloud-based future, but the reality is, we still rely on our phones to hold lots of data, including photos, videos and apps.

When you think about a 16GB phone, consider that about 4GB is taken up by the operating system and default apps. That leaves the user with, at most, 12GB for apps, photos, video and miscellaneous documents.

Photos can take up a lot of space on your phone. Especially if you've upgraded your phone every couple of years and used the same iCloud backup.

I have 11.6GB worth of photos and videos on my 128GB iPhone 6 and those consist primarily of photos taken with my phone. That 11.6GB figure includes every photo I've taken on an iPhone since the iPhone 4S — the last time I did a clean setup on my iPhone.

Tools such as iCloud Photo Library can back up photos to the cloud, but they don't necessarily keep those photos off of your phone. It's true that iCloud Photo Library can take up less space on your phone, storing just thumbnails of individual images — but in practice, iOS 9 tends to take up more space when it's available.

And it isn't just photos. If you capture video with your phone — and given the quality of the iPhone, that's a common activity — those video sizes can get pretty large, too. This goes double if you choose to record in slow motion.

With the rumored 4K video recording capabilities, 16GB isn't going to be enough to store a few years' worth of photos and video and still offer room for new memories down the line.

Yes, users can offload their phone photo storage to cloud services — but again, that adds a layer of friction that would be better served with more space.

A few years ago, it was a big deal if an app was over 50MB in size. In fact, iOS wouldn't even let you download a 50MB file over 3G or LTE in order to help save data charges. Today, the file limit is 100MB.

Beyond that, the upper size limit of apps themselves has increased from 2GB to 4GB, which means games and other apps can take up more space on your phone.

Most apps won't take up more than a few hundred megabytes, but what's the use in getting a phone specifically designed to run the latest and greatest games if you have to delete old games in order to install new ones?

Apps such as Spotify, Apple Music, Disney Anywhere and Amazon Instant Video allow users to download music or videos for offline viewing. This is great for those times you're on an airplane or in an area with low cell coverage.

One of the reasons I've been paying for Spotify for a long time is so I can listen to music playlists while flying. The same is true for Apple Music.

Last week, Amazon Instant Video even started allowing users to download movies and TV shows for offline viewing. I watched The Bling Ring on the C train last week. It was glorious.

Here's the thing: Offline storage eats up your phone capacity. A few hundred megabytes here or there isn't a big deal on the surface, but if your phone is already bursting at the seams, it's too much.

My 64GB iPad Air has become too stuffed full of apps and data. As a result, I frequently have to erase apps or clear out storage caches before heading on a long trip or downloading a new game. And that's with 64GB of storage.

A 16GB phone? Forget about it.

Apple introduced a 16GB iPhone option for the original iPhone in early 2008. The iPhone 3G, released in July 2008, came with an 8GB or 16GB option. Starting with the iPhone 5, the minium iPhone capacity became 16GB in 2012.

Apple already knows users experienced significant problems trying to upgrade to iOS 8 last year because of free space constraints. When it dropped the 32GB space tier for the iPhone 6 and iPhone 6 Plus, giving users the option of 16GB, 64GB and 128GB, we weren't pleased. 

Even in 2014, it was clear 16GB wasn't enough.

But in 2015, with videos and photos taking up more space, games becoming more advanced and offline media becoming a real part of day-to-day life, it's just unacceptable.

Other companies, including Samsung, have forgone 16GB storage tiers on their flagship devices — correctly understanding it's just not enough. Especially when you don't have a way to add more storage via a microSD card.

If I see a 16GB iPhone 6S or iPhone 6S Plus tomorrow, I'm going to be really disappointed. Not for me (I always buy the maximum storage capacity device I can), but for the new iPhone owner or upgrader who doesn't understand that 16GB just isn't enough.