There isn't a single reason — there are four things Lúcido does differently from traditional invoicing software.

Most invoicing programs put a fifteen-field form in front of you. Lúcido asks for the essentials in a chat — client, description, amount — and builds the rest: VAT calculation, numbering, template. Fewer clicks, fewer typos.
Retail, hospitality, renovations, plumbing, transport, design, professional services — the lines of a document are free text, with no templates locked to one sector. You don't need to be a "digital business" for it to fit.
€9/month with everything essential included — unlimited invoices and quotes from the first plan, with no need to upgrade just for the basics.
Verifactu arrives in 2027. Lúcido's sequential, immutable numbering model was built with that change in mind, so you won't have to switch programs when it comes into force.