Not exactly. This becomes true only if you make mistakes. If you don't, you might have progressed slightly less than the others, but just slightly. So when they make the mistakes, and easily beat them thanks to smarter development.
Because if you make mistakes, the choices to undo things are pretty limited: win it all (pretty hard), sell players (with the lottery of the market, that's risky), or downgrade some of your facilities (which is most likely to effectively correct the mistake). And that's what i didn't do in beta, because it took me too long to understand that i've made a mistake. And once i've identified the mistake, beta was about to end, so there was no reason to make any move. Else i would have corrected things way faster by downgrading.
So that's it: no mistakes = maybe a slightly weaker improvement compared to some others... but others that will be forced to downgrade if they want to avoid bigger problems. So they go down to the same level as you. But... they've spent the facility... and downgrading refunds only half the money... and they'll have to rebuild the facility someday... So this particular level will cost them 150% of what it costs to you if you don't make mistakes. And of course, those extra 50% can be used to your advantage to take some advance on your opponents
Others also loose time in the process. Especially with bigger facilities, that are pretty long to develop. So downgrading it + re-upgrading it later on = twice the time. And when going from level 10 to 11, you need 65 days for the construction works. If you have to do it twice, it takes you over a season, and in the end takes more time than going from level 14 to level 15 (65 days x 2 = 130 days, versus 119 to reach lvl 15).
Anyway, it's always the same: the higher you get, the harder it is to stay were you are, and even harder to improve. And after just 3-4 seasons, it will be usual for everyone to have installations at level 10+, which is already 2/3 of the max.
And what's the difference between a level 1 and a level 10 installation? Well, outside of the fact that you already spent 34.5M to go from lvl 1 to lvl 10, the maintenance costs is the real deal here, as it is nearly multiplied by 100. Level 1 costs around 30K of maintenance per season, while level 10 costs slightly under 3M. Then it's multiplied by 10 between level 10 and 15. Now let's say you've got all your installations at level 10, and that's already over 20M of expanses just for the maintenance of the installations!
Of course, if you've got all installations level 10, players and staff progress relatively fast... and so does their salary! So you reach a point when you have more to consider than just the construction costs.
Let's say you're level 10 and want to move on to level 11. The cost is 21.6M, which is not easy to get, but perfectly possible. But the other thing to take into account is that the maintenance cost of the facility will make a jump of nearly 2M more per season, going from 2.9 to 4.8M. 2M is not a lot, really, but if you don't pay attention and build several facilities like this, you can easily reach 10-15M of extra costs, which can hurt badly. And when it comes to practice facility, you have to consider the extra progression pace for the players, which means extra OR when contract renewal comes. And this will affect your whole team, obviously. And knowing that salary improve on an exponantial curve, it makes a big difference. So improving the practice facility from level 10 to level 11 (for example) will not cost you just 21.6M, but more likely around 25-26M in the first season, plus 3-5M every following season. So in 3 seasons, it may cost you over 30M combined, nearly 50% more than just the construction costs! So if you look only at the construction cost before building, you end up in troubles a few seasons later.
Of course, if you think that you can handle the whole cost and that this new level will help you getting better enough results to get better revenues (from gate receipts, sponsor deals, money awards, etc), then it's obviously a good decision to improve. But if you're not so sure, the best bet is to stay cautious and let the others make the mistakes
This is true for every level, but becomes critical around level 10 facilities. And for many guys, reaching level 10 somewhere will be done either by the end of season 3 or the first half of season 4, so it's really not that far away...
I've made a bad decision in season 3, and it hurted me badly in season 5. By the end of season 8 (end of the beta), i had yet to rebalance things in the right direction. 3 seasons "lost" in terms of progression and development. During those 3 seasons, many other teams progressed. And if i was regularly in the playoffs of my league in seasons 3 and 4, i had to face relegation in seasons 6, 7 and 8, and was most likely to be relegated in season 9 if there had been one.
Good rhytm Teemu, keep going! 
Some people have yet to see this... 
"Curiously", they are the same who are asking questions already answered in the guide...
.. dealing with a huge penalty problem in recent games. 