There are plenty of employers that can't afford to pay 180k, not everyone works for Google, Amazon or Facebook.
Here in London you have a lot of companies that look for people with similar experience that have huge pay ranges.
A Sr. Engineer can be making anywhere from 40-45K to 110-120K a year (in general health care pays the least, fintech/finance pays the most, startups in the UK often underpay and equity is a joke if they'll even give you any (like 0.5-1% to single digit employee's straight after the accelerator).
Yes when you break it down not every company gets the same level/quality of talent but the requirements on paper are the same.
As for Salary ranges in the UK most of them post, but the ranges can be pretty huge (my company has a range of 65-110K for Sr. Engineers (which overlaps with both engineer III and Lead Engineer), and while it might appear that it's "well they are willing to pay 110 but they rather pay 60" deal there is another side to the story.
Headcount doesn't makes sense, quite often you might get a head count for a specific position say a Sr. Engineer but the team doesn't need one backfilling positions with lower grades isn't always possible so what end up being is that they'll hire people with the bare minium amount of experience needed to pass the HR filter at the lower end of the pay grade spectrum to keep enough money in their budget for pay rises or to hire external consultants.
So while huge ranges can lead to what some people see as underpaying because some one didn't ask enough or didn't had a large enough salary previously to get more it's also the case that these ranges allow teams and departments to navigate through the corporate bullshit of arranged headcounts and stupid ratios.
When you need to have 2 engineer II for every 4 engineer I, and 1 engineer III for every 5 engineer III and 1 sr engineer for every 3 engineer III and so and and so forth you really needs these huge and overlapping ranges to actually be able to hire people in a way that is sensible to the your team / department needs.
On the more anecdotal side this is what currently actually helped my team a lot we need a Sr Engineer but we don't have a headcount, but since Engineer III on the top end is about the middle field of the Sr. paygrade we can use that with a signing bonus to get the people with the experience and skills we need rather than just effectively waste money on a person that we will not be able to get from.
I've joined as a Sr on an intentionally downgraded backfill on a recommendation from a friend who works in the same department since the pay would be identical near the top end of the pay grade but having another tier to "grow into" would allow me to get a bigger raise in the future since a grade promotion has a 12.5% pay raise by default which means that if I can't get the raises I would like I can always be internally promoted to for a bigger raise, and it's much easier to be promoted from Sr to Lead than taking the tech expert or manager roles since those require more years of experience in the company for an internal promotion (again dumb policies but you can't always fight the system).