The switch is worth it, but it really depends on what you specialize in and how much responsibility you take on. A maintenance technician earns quite a bit more than a base operator, probably somewhere between 30 or 40% more depending on the country and region. The key thing is that the company gives you actual training in hydraulic systems, pneumatic systems, industrial electricity, or whatever they use at your plant. Without that, you're gonna get stuck in an intermediate salary that doesn't reflect what you're actually doing.
The difference between small and large companies is brutal. At a small plant with 50 people, a technician does everything but the pay is on the low end because the company has limited budget. At a large plant with hundreds of employees, there are clear specialization tracks: junior technician, senior, specialist in specific lines, and each level adds real money. Plus at big companies you get access to external certifications, paid courses, and the chance to move up to maintenance coordinator or supervisor.
So here's my advice: before you accept, specifically ask what training they're offering, if there's a career path within the maintenance area, and whether the salary is negotiable based on what you already know about machine operation. If the offer includes a real training plan, take the switch without thinking twice. If it's "maintenance" that ends up being what you were already doing but with a different title, then negotiate better pay before you accept.