No, you don't necessarily need event software for seasonal events.
You can use free tools like Google Forms to collect registrations, spreadsheets to keep track of attendees or vendors, and email to send updates. For smaller events, that setup can work just fine.
The downside is that it usually requires more manual work. You may spend extra time organizing registrations, checking payments, updating spreadsheets, following up with people, and sending event information.
Event software can make that process much easier by putting those tasks in one place. Depending on the platform, you can manage registrations, payments, communication, and other parts of your event without having to piece together several different tools.
The right software also depends on the type of event you're running.
If you're mainly selling tickets to attendees, a platform like Eventbrite may make sense.
If you're running a vendor market, farmers market, or community event that works heavily with vendors, Marketlly is built more around that workflow. Organizers can create vendor applications, collect payments through Stripe, manage booth layouts, send SMS updates, and manage vendors from one platform.
You can absolutely run a seasonal event without event software. But once you're managing more registrations, vendors, payments, and communication, software can save you a lot of time and make the event easier to manage.