Can I Access 2b2t on a Nintendo Switch?

No, 2b2t is only compatible with an older version of the Java Edition client (currently at version 1.12.2 at the time of this answer). You can only join the 2b2t with the specific version of Minecraft that the server is running.

It's theoretically possible - a tool called Geyser lets you connect to Java Edition servers on Bedrock, even on console, according to this video:

It may be possible to connect to 1.12 servers (using VIAaaS), but I don't have a console to test it on, and you do need a Java Edition account (and a PC or Mac) if all of this is possible, so it's more something to do as an experiment, not something to do if you don't want to buy Java Edition.

If anyone does want to do this, here are some useful links:

https://github.com/GeyserMC/Geyser/wiki/Setup#console-setup

https://github.com/GeyserMC/Geyser/issues/607

https://github.com/ViaVersion/VIAaaS (thanks jamestheawesomedude)

I want to know if there is any way for me to get onto the 2b2t server on it?

Yes, there is a way.

For this method, you'll need three third-party tools:

• Geyser (to allow a Bedrock Edition client to connect to a Java Edition server)
• ViaVersion Standalone (to allow a 1.16 client to connect to a 1.12 server (because, despite keeping the server on 1.12, 2B2T's admin has decided not to install ViaVersion.))
• BedrockConnect (to allow a console port to connect to a custom server)

Setup

Geyser (Standalone)

Get a cheap VPS (or just an unused computer at your house); ensure it's got Java on it (preferably version 11 or newer), and run the Geyser Standalone file (Geyser.jar), which can be downloaded from their CI server.

Edit its config.yml and set

• remote→address to 2b2t.org._v1_12_2.viaaas.localhost
• server-name to 2b2t.org
• motd1 to 2B2T Proxy (and remove motd2)
• show-cooldown to false (it's currently disruptive on consoles)

then restart Geyser to reload the changes.

(Also, don't forget to open 19132/udp in whatever firewall the machine may have.)

Remember this server's IP — you'll need it later!

ViaVersion (Standalone)

On a computer or VPS (preferably the same one you're using for Geyser), also with Java 11, download ViaVersion Standalone from their CI server: go to the latest successful run, scroll down to download the Artifact, (unfortunately, this requires a GitHub account — fortunately, these are free;) and extract+run VIAaaS-0.2.#-SNAPSHOT+#######-all.jar from it.

(Also, don't forget to open 25543/tcp in whatever firewall the machine may have.)

In your web browser, go to https://viaversion-server:25543/ (except instead of viaversion-server, actually put the IP or hostname of the ViaVersion Standalone server). You will have to accept and connect to a self-signed certificate.

After ensuring that “CORS Proxy status” is “OK” (if it's not, go to “Settings” and paste https://crp123-cors.herokuapp.com/ — or, if you're paranoid, you could look into running your own — then go back to Home); click on Listen to premium login, and use a Java Edition Minecraft client to follow through with the authentication. Then, click Listen to _your_username_ and ensure it shows it's listening for your UUID.

(Leave this browser window open.)

BedrockConnect

Once your "Geyser Server" and ViaVersion Standalone proxy are running (remember to leave that browser open!), you will need to configure your device* with BedrockConnect to allow it to connect to 3rd-party servers.

(*The Nintendo Switch, Xbox One, and PlayStation 4 require this; Android, iOS, Windows 10, and Fire/Fire TV editions do not; if you are on one of the latter platforms, skip this step.)

To do this, you should change its network configuration; set its DNS to manual: the primary DNS to 104.238.130.180, and the secondary to 1.1.1.1 (or your favorite DNS server).

If you have problems, you might want to try one of their other servers, such as 173.82.100.84; or even host your own.

Once Geyser is running, and your Switch (or PS4 or XBO) is configured to use BedrockConnect, you're all ready to go!

Connecting

Open Minecraft, go to Multiplayer, join any server that has Join to open server list as its MOTD.

Then, log in with your Java account credentials and enter the IP of the GeyserMC server you prepared earlier (NOT 2b2t.org!) as the Server Address.

Quickly look back at the browser on which you had pulled up ViaVersion, and authorize the connection ("impersonation") after confirming the IP's correct.

– et voilà~!