The current feats are lacklustre at best. In general the sometimes amazing feats in core 5e struggle to compete with adding 2 to your prime attribute and that means these ones are not at all appealing. This will apply less to people who do not use 27 point buy as they will often start out (closer to) 20 in their attributes so the opportunity cost is far less, as everything but your prime attribute is worth less.
This especially applies to fighters who have no archetype with "active mundane options" and in standard 5e get feats to give them some. The two mundane fighters have mostly passive boosts.
So here are a few attempts at suitable feats that might be picked instead of +2 STR. Note core lets you choose one of two or three attributes to boost for many feats while none of the Solasta ones do at the moment -I did not follow that. Having +1 to an attribute makes them far more appealing of course being only half an ASI. In fact some of them are very like half a core feat with the 1 ASI added...
Berserker +1 CON You may enter a berserk rage giving you advantage on your attacks and giving advantage to enemies who attack you (like the Orks)
Cleave +1 STR. After you drop an enemy you may make an attack with a melee weapon as a bonus action.
Prodigious Athlete +1 STR, DEX or CON. Climb like a thief (rogue archetype). Jump farther like the spell.
1 DEX or STR. After an enemy misses you with a melee attack and you are not using a shield use your reaction to attack them with a one handed weapon.
Combat Reflexes +1 DEX. You gain advantage on initiative checks. When you make an opportunity attack you do not use up your reaction. When you ready a melee attack you may attack everyone who enters your melee range. (Despite all that I am not sure it is worth having)
Crusher+1 STR Your 2 handed melee weapon attacks ignore resistances. Once per rest you may make a smashing strike with a melee weapon that adds twice your proficiency bonus to damage.
Defensive Stance +1 DEX or CON. You may dodge as a bonus action. Use twice per rest.
(or Defensive Stance +1 DEX or CON. You may cast Blur twice per day) .
Two-weapon Flurry +1 DEX or STR. Make an additional off hand bonus attack. (Once per rest)
Combat Acrobat (Prereq; trained in Acrobatics) +1 DEX or STR. Double your proficiency bonus on Dex (acrobatics) checks. You may disengage as a bonus action.
Whirling Dervish (Prereq; Level 6) You may cast Haste targeting yourself only; use twice per long rest.