Freeze teams are a type of team based on immobilizing enemies and taking advantage of the crit rate buff from the blizzard set and cryo resonance. They are usually composed of two cryo characters, one hydro, and one anemo (for vv/swirl/cc, etc).
Freeze teams have two main drawbacks: 1) not every enemy can be frozen and 2) they usually do not make use of Bennett's broken atk buff, which results in a penalty in their team dps.
Oftentimes when freeze teams do work, it basically becomes an Anemo cc/vv showcase.
Two cryo characters are usually used for cryo resonance +15% crit rate against enemies affected by cryo. Typical candidates include: Shenhe, Chongyun, Rosaria, Ganyu, Layla, Charlotte, Kaeya, Ayaka, Diona, Qiqi, Wrio, etc. Usually one has a cryo dps with a cryo support. Cryo dps include Ganyu, Ayaka, Wrio. Supports include Shenhe, Chongyun, Diona, Qiqi. Sub-dps include Rosaria, Kaeya. Note Eula while Cryo is usually used on physical teams. Eula's claymore hits will shatter frozen targets. It can be used in a type of shatter composition, but here we focus more on keeping enemies frozen. (Even Wrio's CA can shatter frozen enemies, which may make him more suitable for melt.)
Usually the cryo dps will run the 4p blizzard strayer set for +40% crit rate against frozen targets. So in total, the cryo dps can get +55% cr from cryo resonance and 4p blizzard. As people point out, this allows one to stack more crit damage on the cryo dps.
A hydro character is needed for the frozen reaction. Candidates include: Mona, Yelan, Kokomi, Xingqiu, Furina, and in some cases Childe, Barbara, etc. Note on Mona: her Q can get a so-called 'omen extension' on frozen targets, allowing her large dmg bonus buff to last longer. This usually makes Mona one of the best choices for freeze teams in terms of dmg bonus buffing. Second note: since Yelan scales with HP, and freeze teams usually do not run Bennett, that can make Yelan a more preferable choice than Xingqiu for freeze teams.
Lastly an anemo character is used for vv shred, cc, swirl, etc. The best candidates include: Venti (cc), Jean (healing), Kazuha (dmg bonus buff), Sucrose (EM buff). These anemo characters are basically universally good for most teams in the game. Not much else needs to be said on their talents.
Anemo drivers such as Scaramouche can also work in freeze teams (example Scara, Charlotte, Focalors). If a cryo XQ/Yelan/Furina ever releases, that would be great for freeze too (can enable more hydro on-field dps with off-field cryo). Charlotte E is a step in the right direction, but we are looking for more uptime and longer duration like Nahida. See subdps for a detailed discussion.
Most freeze teams will not have Bennett, so divide team dps by 1.5 (a penalty of 33%). From the anemo vv character, RES is reduced by -40% giving a 1.27 increase in dps. Cryo resonance + blizzard strayer gives +55% cr. Expected damage is proportional to $$x = 1+rd$$ With 55% more cr the new damage becomes $$x' = 1+rd + .55d$$ The damage increase is $$R = x'/x = 1 + \frac{.55d}{1+rd}$$ Note a Bennett team can have the atk buff plus melt (giving roughly a 1.5*2 = 3 times multiplier). It is unclear how freeze teams can achieve a similar 3 times multiplier without Bennett to compensate. To maximize R above, note the base crit rate is usually \(r=.05.\) Only for \(d \approx 5 \) or more can the damage increase R reach 3 or more. This corresponds to 500% crit damage, which is basically impossible to achieve in practice. Even with 300% crit damage, R can only give around 1.43 times more damage. So the blizzard set fails to outdamage Bennett melt teams.
So why use freeze teams at all? The real benefit of freeze teams (when enemies can be frozen) is that when the enemy is immobilized, it makes it easier for all attacks to hit. If the enemy jumps around all over the place and is not frozen, that might result in some inefficiencies. Some attacks may miss and so on. Freezing the enemy makes efficient gamemplay ('playing optimally') easier to achieve. But if you're already playing optimally in the first place, melt teams can usually give higher dps.
But otherwise, between 2 Cryo-hydro-anemo and 2 Cryo-Bennett-Anemo, the Bennett melt team can usually do more damage (you get Bennett's buff plus melt). Examples include Shenhe-Bennett-Kazuha-Ayaka, Bennett-Kazuha-XL-Ganyu, and similar melt teams.
The only real way for a freeze team to match, nevermind out-dps an equivalent melt team is if the hydro slot provides a significant buff or sub-dps that can match or outdamage Bennett's atk buff and melt. You would basically need to fit someone like Yelan or Xingqiu to provide off-field dps or bring Mona with her dmg bonus buff and TTDS.
Also Bennett can heal. One can argue that if you're freezing all the time, you may not need a healer. But if something like corrosion hits, then at least bring someone like Jean.