And I've seen Delphi apps; I recently worked on one. In my experience they don't look great. Maybe you've done a lot of work to theme the controls; if so, wonderful. But what I'm familiar with just brought up Windows dialogs, and ... well, that's functional but I wouldn't say it looks great.
But here are a few examples of ways you could create 150 fields in a day on a web app and have them look great:
Arrays of control types: https://formik.org/docs/examples/field-arrays for simplicity of creating the controls plus something like https://chakra-ui.com/docs/components/input to make them pretty.
Spreadsheet look (with spreadsheet functionality!) in one control: https://www.npmjs.com/package/react-spreadsheet
Want to build the form by hand and customize it? https://www.form.io/
Form should follow a database schema and automatically display database records? https://marmelab.com/react-admin/ (I used this approach to bring up an admin panel for more than 150 fields, though spread over a couple dozen pages, because of course that looks better than trying to bring up 150 fields on one page.)
The standard way to create a large form (or any data table on a page) today is to iterate over the fields you want and add them to a page. There are frameworks like Chakra that can help you make everything look attractive--and you can theme the result in whatever color scheme or styles you like.
I really don't want to have to touch Delphi ever again; it felt like I'd fallen back into the 1990s in code development terms, and I missed all of the modern features I'd grown accustomed to. If it's what you like, and it pays the bills, then enjoy. But know that people who have used more recent tools like myself consider it to be anachronistic.