Open-source developments differ greatly in their effort. The open-source software can be very favourable depending on the functions selected, especially for simple projects. However, as soon as complex extensions are required, the available customisation options reach their limits. If, as is usually the case in web design, work is done on a theme basis, subsequent extensions are difficult to implement. For this, the code must be changed, which is hardly possible without web-design experience. An extension of your site is usually not included in the maintenance contract.
If the relaunch of your site is to be visually sophisticated and flexible, a modern, visual development is the better approach. SaaS solutions such as Webflow enable customisation in the frontend, allowing you and your web designer to provide for expansion  quickly. Existing building blocks are simply picked up again and copied for this purpose, without any points of contact with the page's code. Complex extensions are therefore not necessary with professional applications such as Webflow.