Do you need a Trust if you have beneficiaries on all accounts and if you have a Transfer-on-Death deed for real estate?

No, you do not unless the purpose of the trust is to control how the beneficiaries use what they inherit from you. People tend to overuse trusts, thinking they are the way to avoid the delays and costs of probate. But as you apparently understand and have done, there are other mechanisms to transfer assets (beneficiaries on accounts; TOD) without them going through your estate or probate.
The only reasons to really use a trust for inheritance purpose is:
1) If you don't trust the beneficiaries to manage their money or assets properly, so you put them in a trust and have the trustee manage them for the beneficiaires. Example: a child with an addiction or mental/emotional problems--rather than give them money, which they may waste or spend on their addiction or be tricked out of, a trust can dole the money out to them periodically or as needed for certain things (e.g. housing, medical care).
2) If you want to make sure that only a portion of the assets go one generation (e.g. your children) while making sure that there will be assets for future generations (e.g. grand- and great grandchildren): the trust can invest assets and pay out the interest or proceeds to the children, while making sure that the principal remains to provide income for later generations.
3) For charitable purposes: instead of giving a lump sum to a charity or charities, a trust can be set up to invest and grow the money in it, while making periodic charitable gifts over time.