SeaMonkey stands apart from many current browsers because it comes from an older idea of internet software: one suite for browsing, email, and related online tasks instead of a collection of separate apps and services. For some users, especially those who prefer traditional desktop workflows, that is still a meaningful appeal.
It is especially suitable for users who already know they want an integrated internet suite or who are comfortable with classic desktop software patterns. If your workflow values having browsing and communication tools in one long-lived environment, SeaMonkey can still be interesting.
What makes it worth keeping is coherence for a certain kind of user. Instead of assembling several small tools, the suite offers a more unified approach that some people still find efficient and comfortable.
The tradeoff is that older-style integrated software may not match the polish, pace, or website compatibility expectations of mainstream modern browsers. SeaMonkey should be judged carefully against the real sites and tasks you use today, not against nostalgia alone.
My recommendation is to try SeaMonkey if the idea of a classic all-in-one internet suite genuinely fits your Windows habits. Use it on real websites and communication tasks early, and keep expectations grounded in practical compatibility rather than sentiment.