Do you remember on very small power supply board with 5V/1A output?
So, here is other power supply board, but with 3.3V output and up to 3A.

It can power arduino boards, ESP8266, ESP32, GPS or GSM module.

The seller wrote on the website, if you want to use the power board long time, the maximal output current should be 1.8A. The board is not so small (22.3 x 17 x 4.2 mm) like 5V version, but it is also easy to include to your project.

The input voltage range is 5.3 V up to 26 V. The seller wrote that the efficiency is up to 96% and the output voltage ripple is maximal 30mV. The size of board is 22.3 x 17 x 4.2 mm.

The price of board is 2.60 USD with (free) shipping. If you buy 10 pieces, the price for one piece is only 0.9 USD.

One piece: https://www.banggood.com/DC-DC-12V-5V-to-3_3V-Step-Down-Voltage-Regulator-Power-Module-p-1083356.html

Ten pieces: https://www.banggood.com/10PCS-DC-DC-12V-5V-to-3_3V-Step-Down-Voltage-Regulator-Power-Module-p-1102910.html