I worked in the EDA space for a while and even built an online circuit simulation tool [0] while there. I'm aware of couple of startups such as [1] that tried to move these tools to the browser. There are a number of challenges that make web apps difficult in this space such as"
1. Pricing model: For the simulation side of EDA, you need a lot of computing power. With desktop apps, the user already has a powerful machine available that you don't have to pay to use. With the cloud, you need to pay for all the machines so finding a pricing model that works is a challenge.
2. User expectations: The users who are willing to pay > $100k/seat/year expect very advanced features that would probably take 10s or 100s of engineering years to get working. These users also don't care as much about the UI/UX problems that a modern app would solve.
1. Pricing model: For the simulation side of EDA, you need a lot of computing power. With desktop apps, the user already has a powerful machine available that you don't have to pay to use. With the cloud, you need to pay for all the machines so finding a pricing model that works is a challenge.
2. User expectations: The users who are willing to pay > $100k/seat/year expect very advanced features that would probably take 10s or 100s of engineering years to get working. These users also don't care as much about the UI/UX problems that a modern app would solve.
References
0. https://www.multisim.com/
1. https://upverter.com/