My sister transferred from a top LAC, and tops in her major(s), to a flagship. Loved every minute at her second school. She honestly just couldn’t afford the LAC and couldn’t afford to keep up with the Jones (or really the Rockefellers and Vanderbilts) at the LAC. Her fit was much better at the flagship.
If YOU look at it as a downgrade, it will be. If YOU embrace the new school for everything it offers, it will be a good decision for you.
Another option is to take a semester at another school without withdrawing from the LAC you currently attend. Most schools have exchange agreements or would let you take credits and transfer them back. Go speak to the exchange people. One issue might be the FA as you have to be enrolled in a degree seeking program to get federal aid and usually state or school aid. My daughter’s (big public) school would allow a semester at another school and the student would pay whichever tuition was cheaper and still get the FA from that school. ie, she could have gone to her own state flagship and paid that tuition which was cheaper than where she was, but kept her aid from the OOS flagship she attended.