You get what you pay for.......
The more successful sports would struggle to get by without having well paid and highly competent refs and judges.
Most Americans saw what happened when the NFL tried to play with less experienced/amateur refs.
In fact the pressure became so great after a series of blunders that the NFL gave the real refs everything they were asking for.
There are a LOT of significant differences between the ISU and the NFL, so other than the general point that professional officials would do a better job, there isn't much scope for comparison between the two organizations. Soccer, being a worldwide sport, or tennis, which like skating is also competed by individuals and duos rather than location-affiliated large teams, might make better models. I confess I have no idea about how those sports manage their corps of officials.
Still, I'm curious about the skating judging corps could be professionalized . . . How we would get there from here would be a whole other level of complication to address later, once we know where "there" is.
Let's say the ISU adopts a policy of hiring professional judges accountable directly to the ISU with no national affiliations (although obviously everyone comes from somewhere).
There are several tiers of international events for which the ISU might hire officials:
ISU championships and Olympic Games (4 or 5 large events per year)
Grand Prix (7 small events per year) and any other elite invitational events such as Japan Open that they might sponsor themselves or approve if sponsored by national federations
Junior Grand Prix and the major "senior B" events
Figure skating included in regional and/or age-limited international multi-sport festivals such as Youth Olympic Games, World University Games, Asian Games, etc.
Competitions hosted by national federations or even local clubs that are open skaters from countries outside the host federation, that may combine senior, junior, novice, and lower level events
And then there are national championships, qualifiers for national championships in larger federations, and local club events --some of of them attracting only or mostly low-level skaters -- that do not include foreign competitors and would not be expected to rely on international judges
So which of these competition tiers should require only professional judges? Would there be enough such competitions to sustain several professional judges from each continent/region that has skaters competing at that level, at a livable yearly salary in addition to travel expenses? Or would they be paid moderate fees per event, traveling around the world every week or two during the height of the season, and need other sources of income to sustain them the rest of the year? Would there be any prohibitions on what other professions a professional judge could engage in (e.g., coaching, even if only at a beginner level, or even if only many years ago)?
Which events might use mostly lower-level amateur judges and also invite international pro judges to participate? Would the organizing committees have to pay salaries as well as expenses to the pro judges? Would the pro judges be allowed to volunteer their time if they choose to judge at a local competition near where they live?
Which events would rely only on volunteer officials -- maybe not even be allowed to use professionals even if they could afford it?
Would large federations tend to use only or mostly professional judges who live in easy travel distance for their national championships and other important domestic events?
What would be the pathway from domestic amateur to professional international judge?
How many tiers of international appointments would there be (comparable to the current "International" and "ISU" judging appointments)? To what extent, if any, would national federations be involved in shaping a would-be professional judge's pathway into that career?
Should international competition circuits also be restructured at the same time that the judging corps is restructured?
All details that would need to be figured out -- at least the basics before any attempt to transition to a professionalized system.