Things are changing lot online the last few years.
I think that you can find this said by several somebodies every year since 1994 (the year after the launch of Global Network Navigator (GNN), the first commercial website). And it's been true each time. However, what those saying such (usually) actually mean is that things were changing (for the worse) for them.
I also believe that we are entering a phase were there is now a middle tier.
That middle tier began ~15 years ago as niche major B&M enterprises began to see the web as more than an investor info brochure. By about a decade ago enterprise sites were increasingly dominating their niches for certain queries. Some of the early sites, i.e. Amazon, eBay, Google, PayPal, grew large enough fast enough or in new niches carved out online, to also dominate and hold their own with the more established zillion dollar businesses.
I fit very nicely into that middle tier and I meant to right from the beginning. And so did a good many folks that got their start 'back in the day'. Yes, entry level was lower back then, less forest for individual trees to have to stand out from. But there was also another stark difference. Many/most of the pioneers (1994-2000 - end dotcom bubble) and early adopters (2001-2005 - launch of WordPress) of web businesses had 'background'. They were hackers/programmers, had run or used BBS's, saw the opportunity of the web for their existing business, etc.
The divide in that period after 2005 can be seen most starkly in the shift from mostly folks who were used to figuring things out for themselves who asked for a hint or pointer when stuck to increasing numbers of folks who demanded a step by step how to and instant gratification/success; and got seriously upset when told to do a simple search for ye olde asked/answered basic questions.
Note: not pointing at anyone in this thread, merely a general observation.
Another divide started about then as well and grew quite slowly if obviously to those few of us on the 'out' side: the divide between all things Google and Google for all things side and the Google Search/AdWords/AdSense/etc is but one part of the online/web business model puzzle. And now that the Google 'alone' business model is increasingly problematic for many it is even harder for them to shift, both mentally and technically, to a more holistic approach. Those changing now/recently...
* to responsive sites are years behind competitors;
* to a mobile first progressive enhanced site design are years behind competitors;
* from drop ship of commodities are years behind comparable competitors and/or being trampled by enterprise;
* to actively identifying and blocking 'bad' bots are years behind competitors;
* from third party ad/af networks are years behind competitors;
Also... pretty much year in year out...
* users and their connection contexts change;
* SE queries and query results change;
* SM platforms, their audiences, and behaviours change;
* Link rot changes all sorts of things;
* competitors behaviour/offerings change;
The real question to ask is how 'you' are going to adapt to all these and more changes that have already occurred and those that are about to and those that may in years to come.
Now I admit that I had it 'easy' in some ways, having:
* decades of life experience;
* decades of (B&M) business managerial and ownership experience;
* decades of programming, DB design/GUI experience;
* almost a decade experience building client websites by hand;
* the luxury to be semi-retired, not reliant on sites to cover living expenses.
However I also:
* put in much of a decade of 100 hour weeks, week in week out; now it's a mere 40ish.
* put in years of networking at niche and ad/marketing conferences, etc. marketing my sites;
* had (and have) a rolling five year business plan attempting to not be surprised;
* picked niches that were not the 'popular' 'obvious' money makers so as to minimise competition and make domination easier;
* put in significant personal R&D and site design time to stay ahead of the web curve;
* invested significantly (monetarily) in double blind translation to offer sites in three colloquial language versions other than English;
* invested hugely (personal time) in an analytics backend including real time personalisation (now pseudonymised per GDPR);
And had a whole lot of luck along the way.
Am I fortunate? Yup.
Did I, do I, work my proverbial rear off to help Dame Fortuna? Yup.
I use Google and FaceBook et al, and when they want more than I'm willing to share I cut them off at the knees aka block whole sections of sites from their purview. Given the way they are developing I expect them to be totally blocked within 5-years. If that happened now it would cost me about a quarter of my traffic and a fifth of my revenue. In five years? I'll see then. Because I expect to still be here and prospering. My business plan says so. :)