99% of business in this situation, you would never call a startup.
New law firm.
New dental office.
Your uncle started doing roofing, asks your little brother to work his summer off from Uni with him on roofing.
A new golf course installed in a coastal area.
A 50 new homes going up in the suburbs.
The empty spot on the corner is now a little corner store - beer, wine, chips.
New taco restaurant down the street.
Nobody is calling these situations (i.e. the vast majority of new business) 'startups. So clearly there is a kind of de-facto popular lexicon - and it's not 'startup'.
And many new businesses are just called new businesses. Like the guy who started selling modified skis at the ski resort. That's usually referred to as 'small business'.
A group of people doing some kind of new thing who are maybe not seeking funding but could possibly seek VC funding ... this is more in the realm of what we call 'startup', wherein there is generally a larger market opportunity, and possibly higher growth ... this is startup.
I'd argue that a trait shared by many startups is talking about themselves in the best light possible to get people focused on their future potential, and to me that leaves room for considering a bunch of mega success wannabes cranking out code on Twitch as startups in a startup competition. Shipping, failing fast, getting feedback, pitching... They all sound like startups to me, so that's what I'll call them. May the best startup win!
In reality, nobody is calling their new law firm a startup.
Nobody is referring to said law firms as startups.
Now - if it's a specialized kind of firm that sells services online, like a 'law marketplace' or something, maybe they will call it a startup.
Yes - the term startup is quite varied ...
However, the vast majority of business generally don't apply, so there is at least some kind of 'critical mass' to what we mean bu the word.
Generally 'a business' is not 'a startup'.
I am sure that without ambition (i.e. just serving a single city) or without tech (i.e. just building one conventional law firm in every city) it would not be called a startup.
I'm quite sure that the dictionary definition is the one that most people will agree with. Silicon Valley did not create the word and so don't get jurisdiction over its definition. https://www.merriam-webster.com/dictionary/startup Words and language evolve over time according to usage. The word startup hasn't evolved to that point yet, despite what prominent tech investors and founders would say.
I'm not even in the Silicon Valley, nor is is the observation of the popular usage of a term 'arrogant'. It just 'is'.
Nobody is calling a regular roofing company a startup. If said roofing company is doing something entirely different, and probably growing at an accelerated pace ... like developing a new kind of integrated tile and application process ... then maybe people would refer to this as a startup.
Oh, so a startup is a business that continues to fail and hasn't screwed over it's users yet. Gotcha.
The term startup is ambiguous and the fact that Steve Blank, Eris Reiss and Paul Graham have their own definitions says something.
It's hard to not call Pieter Levels' Nomadlist a startup.
It's infinitely scalable and makes a profit.
I'm not sure your qualifications of a startup, but that's better than 90% of TechCrunch startups who are reliant on humans to scale and burning cash.