Does a revocable trust serve to avoid the need for a guardian?

Yes, at least with respect to your financial affairs and assets are owned by / have been transferred to the trust. If you are elderly, it often makes sense to create a revocable trust and have title to your assets in your name as trustee of the trust. This assists in the management of your assets if you become too ill to handle the assets yourself. This also avoids the need for a guardianship through the court and avoids the necessity of your successor trustee filing any reports with a court. The cost and time savings are enormous. But it’s important that asset ownership be in the trust, a task that is relatively easy to accomplish.